Latest / Rounding Up / See It! Say It! Symbolize It! with Dr. Patrick Sullivan
Transcript
- 0:00Representations, language, and symbols are all important ingredients
- 0:05in building students' conceptual understanding and fluency.
- 0:09But how can we understand the relationship between those three ingredients?
- 0:14And what happens if we leave any one of them out of the recipe?
- 0:17We'll explore these questions today with Patrick Sullivan,
- 0:21a professor of mathematics at Missouri State University.
- 0:26Welcome to the podcast, Patrick.
- 0:27It's so great to have you joining us today.
- 0:30I'm excited to be here. Thank you for this opportunity.
- 0:32So you've written a book, it's called See It,
- 0:35Say It, Symbolize It. And early on in the book,
- 0:38you tell a story about your Grandma Edna,
- 0:40and I love this story. You talk about the role that she played in your math journey.
- 0:46So I wonder if you could share that story with our listeners.
- 0:50Yeah, my grandmother played an instrumental role in my life.
- 0:52She passed away about four years ago,
- 0:54about nine, at 99 [years] and 20 days.
- 0:56So very good full life. But ~ a little bit about her.
- 1:01She grew up in a small town in Missouri,
- 1:03was a valedictorian to that school in class of 1939,
- 1:08and didn't have an opportunity to go to college,
- 1:10so she ended up going to hairdressing school.
- 1:13So part of the story was to honor her life in sharing that story,
- 1:16but there's a poignant moment of my life,
- 1:19where
- 1:19I'm in elementary school and I'm this kid that,
- 1:21with allergies, so I'm carrying around a handkerchief.
- 1:24You know, my two favorite subjects are recess and lunch.
- 1:27~ I stuttered, and I I didn't read very well either.
- 1:32So There was not a whole lot where I felt like school was a winning place for me,
- 1:37but that one thing that I felt like I was good at was math.
- 1:40Things were going OK. I wasn't going home in tears.
- 1:44And along came 2-digit multiplication.
- 1:47And I remember vividly that day,
- 1:49just feeling devastated, like,
- 1:52"OK, this is it." And the worst part of it was—again,
- 1:56my two favorite subjects are lunch and recess.
- 1:58They didn't take lunch away—but we had to stay in for recess,
- 2:01which was crushing, 'cause I loved recess.
- 2:06So I was pretty distraught when I got home and [it was] one of those moments
- 2:09in life where things just were not going well.
- 2:12My, both my parents were were looking for different jobs,
- 2:14so they weren't there, but I was
- 2:16I was blessed with having my grandparents next door.
- 2:18So I go over that night, and my grandmother could tell something was wrong.
- 2:22And so she asked, and I said, "Well,
- 2:24I just cant figure this 2-digit multiplication business out." She
- 2:29got out these 3-by-5 cards and this ~ mechanical pencil,
- 2:32and she just wrote down at the top,
- 2:35"35 times 24" at the top of this card.
- 2:38And she said to me, "Do you know what 4 times 5 is?" I said,
- 2:41"Yeah, 4 times 5 is 20, 4 times 30 is 120,
- 2:4620 times 5 is 100, and 20 times 30 is 600." And she just explained that to me.
- 2:53She wrote the header above the number,
- 2:55she wrote the place value, and she talked about how the 20 was really 2 tens
- 3:01and the 30 was 3 tens. But it,
- 3:03it just all clicked. I mean, it was amazing.
- 3:06We spent the next hour and a half doing that.
- 3:09And the crazy part of it is, the next day in class,
- 3:13I felt like
- 3:14I was on cloud nine. I got it.
- 3:16And not only did I get it, I could explain it.
- 3:19And so the next day, there were about five of us in what I call,
- 3:23lovingly, math jail. And so I explained how I did it.
- 3:27The teacher gave me the space to do that.
- 3:28And I and I'm forever thankful for that.
- 3:30She could have just could have said,
- 3:31you know, "No, that's not the way I do it.
- 3:33So we're not gonna do it that way." But she let me go up to the board and show
- 3:37it to my peers. And then as my peers got it,
- 3:41they were like, "Oh, yeah, that's makes a lot of sense."
- 3:44And so that again, really elevated my stock.
- 3:47You know, I really, I felt like a million bucks there,
- 3:50like, "I'm the math guy now." And after that day we all were out of math jail.
- 3:55And so we all got to leave. And I I felt empowered.
- 4:00And that one day changed everything for me.
- 4:04And still, to this day, I'm 50 years removed from it,
- 4:06and it still brings back the emotions.
- 4:09There is so much in that story,
- 4:11Patrick. So I think I wanna, I wanna toss you another question.
- 4:15There are a lot of things in that story that spoke to me that validated some
- 4:21of the experiences I had as a kid.
- 4:22There was wisdom ~ both in how Grandma Edna helped you and also what your teacher
- 4:28did in response. But I wonder if you could be transparent with folks and
- 4:32say some of the meanings of that story that you think are important.
- 4:36You know, I want to make a point about how one moment in math around a
- 4:40big idea can change a trajectory for life.
- 4:42And it truly did. I mean that,
- 4:44to me, I—I go back to it and I remember it so vividly.
- 4:47You know, and it doesn't take much to get out of what I call "the math game."
- 4:51You know, the top three areas I often hear are fractions,
- 4:54multiplication, long division.
- 4:56You know, even when I ask adults when they say that they're not good
- 4:58at math and, and for me, this book is about redemption.
- 5:02It it's about a chance for people who said
- 5:04I've never really been good at math.
- 5:05Well, here's a different take on it.
- 5:07This is where you can get back in the math game and see math as a different
- 5:11in a connected way to think about.
- 5:13Because that story for me is a lot about seeing ideas that were disconnected.
- 5:17And in one stroke, in one conversation,
- 5:19she connected a lot of ideas. It's not only from the perspective,
- 5:22as I said, from what I learned,
- 5:24but I give it a lot of credit—I talked a lot about my Grandma Edna,
- 5:27but my teacher also gave me a platform to share my thinking with others and,
- 5:32again, in the 1970s, that was probably unheard of.
- 5:34That was the [era of] "Sit down and do your work and don't say anything".
- 5:37So for the teacher to do that,
- 5:39and not just reject what I wanted to share,
- 5:42was empowering.
- 5:44You know, when I first saw the title of the book,
- 5:47I really imagined that See It,
- 5:49Say It, Symbolize It might be a set of steps in a sequence.
- 5:53But after reading the book, I think I'd describe See It,
- 5:58Say It, Symbolize It as ingredients in a recipe.
- 6:02And I wanted to ask you: How do you think about the relationship between
- 6:07the three phrases in the title—See it,
- 6:09say it, and symbolize it?
- 6:10OK, first all, I love the analogy.
- 6:12I'm stealing it. I'm gonna use that from now on.
- 6:15It's a combination of what makes the recipe work.
- 6:17And as I've done many times in my ~ cooking experiences,
- 6:21if you leave one of them out, the results are not the same.
- 6:24You know, and so the "see it" part is the main ingredient.
- 6:27It's the base. Maybe that's like flour or something.
- 6:30But anyway, it's it's the base.
- 6:31For me, it's the foundation. And the "see it" part is
- 6:35the representation activities that are used to make the mathematical idea most
- 6:39visible.
- 6:40So for example, let's consider 2-digit addition.
- 6:43And we can think about either a horizontally written problem or
- 6:47a vertically written problem, a 2-digit problem.
- 6:49But many teachers utilize base ten blocks or bundled popsicle sticks.
- 6:53They're great manipulatives to teach addition.
- 6:56But then what type of activities do we engage students in with them?
- 7:00So it's not just the representations that matter,
- 7:03but it's how we utilize them and the activities we engage students.
- 7:06So
- 7:06I like base ten blocks, for example.
- 7:08They make the idea of equal exchanges explicit because you can hand me
- 7:1210 ones and I'm going to give you 1 ten.
- 7:13There's this switching out that happens.
- 7:15There's an exchange. But with bundling popsicles—the sticks—what's,
- 7:19what's most visible is that when you bundle those,
- 7:21you have the 1 ten as a bundle,
- 7:23but you still have the 10 ones.
- 7:25It's there. So it's still visible.
- 7:27So it's really tied to
- 7:29our learning goals and and being very intentional with the representations
- 7:32we use and the activities that we engage students as we're doing that.
- 7:36I think the "say it" part is about students communicating their understanding.
- 7:40You know, I think, just very basic when we're thinking about addition,
- 7:44you know—old school the way I learned it,
- 7:46you know—you carry the 1 and we regroup.
- 7:48But the idea is, and I'll talk more about this later,
- 7:51but this idea of equal exchange:
- 7:52What are we exchanging? And by doing that,
- 7:54we're taking 10 ones and replacing it with 1 ten.
- 7:58And that happens throughout mathematics.
- 8:00And I feel like with the "say it" part is,
- 8:02to me, like the egg of a recipe.
- 8:06It binds everything together. And I feel like that,
- 8:09many times, is the missing piece there that,
- 8:12you know, you've done this great job with these physical or visual representations,
- 8:16and then you jump right into the symbolic and there's no connection between the two.
- 8:20It's just one more thing to learn.
- 8:21And so there's a disconnect between what you've done with the representations
- 8:26or the models
- 8:27and then what you're doing symbolically.
- 8:29So I think language is the binding part.
- 8:31And then the symbolizing kind of works two ways.
- 8:33The first is: Obviously, when you take a number—like 74,
- 8:38for example—that knowledge has to be shared and imparted on somebody else.
- 8:42It's not something they're just gonna know that the 7 is 7 tens and the 4 is 4 ones,
- 8:47that we're operating in a base ten number system.
- 8:50That just doesn't happen from a constructive standpoint.
- 8:53You know, there has to be some judicious telling.
- 8:56But then there's also this element of symbolizing where when
- 8:59you give students something like 7 times 3,
- 9:02how are they making sense of it?
- 9:04How are they symbolizing that now that you've shown them something symbolically?
- 9:07How are they symbolizing?
- 9:09So those three things bind together.
- 9:11And oftentimes I see we rush the symbolizing and hide the seeing and the saying,
- 9:17and then we wonder why students struggle with mathematics.
- 9:21I really love how you unpacked the relationship between those,
- 9:24Patrick. And I do want to go back and talk about "see it" because— —one
- 9:28of the terms that you used in the book that I thought was really interesting
- 9:32is this notion of a concept image.
- 9:34And I wonder if you could share a little bit about what a concept image
- 9:38is and the theory behind what a concept image offers to students.
- 9:43I'm using Vinner & Tall's definition from the early 1980s,
- 9:48but the concept image—you we have a concept definition of what something is,
- 9:51whether it be a triangle or a fraction.
- 9:53But then we also have the concept image.
- 9:55What do we as the individuals,
- 9:56that total cognitive structure that we associate with the concept?
- 10:00And so we want those things to align at some level,
- 10:03but there's a lot of things, different associations that go into it.
- 10:07So
- 10:08let me give you example of a fraction.
- 10:10The concept definition of a fraction,
- 10:11for students based on a third grade Common Core standard,
- 10:14is the fraction "m over n" is m copies or iterations,
- 10:18a quantity that can be counted,
- 10:20how many of a unit fraction 1 over n,
- 10:23a unit that can be measured, like how much.
- 10:26So with that in mind, we as teachers are challenged to provide students with
- 10:29experiences that align students' concept image with that concept definition.
- 10:36And that's often dependent
- 10:37on students' first experiences with fractions and the representations that
- 10:41are utilized.
- 10:42So the problem is, as I review many US curricula,
- 10:44what they see due to an emphasis on—I call a missing piece area models.
- 10:48Like, you have this area model that's been separated into eight pieces
- 10:52and seven of those are shaded,
- 10:53is a concept image more aligned with m pieces shaded out of n total pieces,
- 10:58which to me is the underlings of a ratio,
- 11:01but it fits more with that interpretation than seeing fractions as numbers.
- 11:05So
- 11:06those experiences, at least in the beginning,
- 11:08need to initially engage in activities with models that make
- 11:12the unit fraction explicit. For example,
- 11:15given a length of one unit and a length of part of that unit that represents
- 11:18a particular unit fraction, how can we describe the length that lies somewhere
- 11:21between 0 and 1 while engaging them in the activity of—if we're going
- 11:25to talk about iterating, then are we in engaging them in iterating or making copies?
- 11:29So I think if the iterated length is the same length of the whole after three
- 11:33iterations,
- 11:34we have a name for that, and that's one-third.
- 11:35And the reason why it's one-third is because three copies of that unit length
- 11:39of one-third is the same length of the whole.
- 11:41So thinking about the language that I want that to align with the experience,
- 11:45we really want them to see and develop a concept image of fraction
- 11:49as a measurement that involves a unit,
- 11:51and it's derived from a different unit,
- 11:53which is the whole. So we've got that units of units perspective.
- 11:57And so if that's the goal and the concept definition is applied to that idea of
- 12:04m over n as being iterations of that unit fraction,
- 12:08that we want the experiences students have have to align with that.
- 12:11You know, something that you said,
- 12:13I wanna just hold on it for a second.
- 12:15I really appreciated that part of what we're trying to do when we're in
- 12:19the "see it" phase is think about what explicit features we really want
- 12:24to be thinking about. Whether it's a visual model or a manipulative,
- 12:28there's a need for like a close analysis of:
- 12:32"What does this model
- 12:35help them see?"
- 12:36Yes.
- 12:36I think that calls for us as teachers to really interrogate the models that
- 12:40we are putting in front of kids and then look back and say,
- 12:43"To what extent do these actually reflect what I want my kids
- 12:46to understand?" Does that make sense?
- 12:48Ab, absolutely. You know, I had teacher ~ experience where she asked us
- 12:53to to come in her classroom, and we did some interviews and a lot
- 12:56of students were saying that the fractions five-,
- 12:58six-, and seven-eighths were equal.
- 13:00And she was shocked because she'd never told them anything to think that five-,
- 13:04six-, and seven-eighths were equal.
- 13:06But then we said, "OK, so let's look at your instruction,
- 13:10and let's talk about it. And so one of the activities that
- 13:12she did with students—it's a great activity,
- 13:14and and I I wanted to honor the teacher in that idea—but we started
- 13:17to think about, "Well, what could lead to this?" And so,
- 13:19what she did is she had a fraction tower that had a sheet that had halves,
- 13:23thirds, fourths, fifths, sixths,
- 13:26eighths, tenths, twelfths. And so when she was doing fractions,
- 13:30she was having students for like the fraction three-fourths put a jelly belly
- 13:34on each of the one-fourths. So,
- 13:37with five-, six-, and seven-eighths,
- 13:39guess what? There was one jelly belly missing.
- 13:41Yep.
- 13:41So we're not attending to the size of the unit.
- 13:43So there was a misalignment between the understanding that she desired
- 13:47and the activity that she was engaging students in.
- 13:50And so just by having that conversation,
- 13:52we were able to shift the focus a little bit.
- 13:54And again, this teacher was doing the best they could.
- 13:56I, I'm not faulting the teacher at all,
- 13:59but just really being reflective on,
- 14:00as you said, those representations or models that we use and is there alignment with
- 14:05the learning goals that we have.
- 14:07Gotcha. Yeah. That's a great example.
- 14:10So I would love to shift and talk about some of your ideas about language.
- 14:14So this is the "say it" part of the book.
- 14:15OK.
- 14:17Let's start with a big broad question.
- 14:19You talked about the role that language plays.
- 14:21You said that it's the stuff that binds.
- 14:24I wonder if you could talk a little bit more about what you mean
- 14:28by language playing a role of binding,
- 14:30especially when it comes to elementary math classrooms.
- 14:33OK.
- 14:34So there's two main reasons that I think it's important.
- 14:37And, you know, again, using your analogy,
- 14:41you know, I feel like it's underutilized,
- 14:43and it is the egg that binds everything together.
- 14:45And obviously, if things aren't binding together,
- 14:47let's say you're making cookies,
- 14:48and you don't put an egg in it,
- 14:50it's not going to bind together.
- 14:51It's just going to be this chunk,
- 14:52you know, you're essentially making,
- 14:53probably granola or something.
- 14:54I don't know.
- 14:55But we have models but no way to bind them together.
- 14:57And we often wonder why students easily use base ten blocks to solve
- 15:01an addition problem, but then struggle to connect those actions
- 15:04with what they do symbolically.
- 15:05I had this conversation with a group of teachers yesterday.
- 15:08Think about the problems—I'll give the,
- 15:11you know, 34 plus 58, and then just for semantics,
- 15:14just say 0.34 plus 0.58. And so part of that binding language together
- 15:20in those ideas, many students—again,
- 15:21my adult learners—see those as two different ideas.
- 15:24There's this conceptual divide between addition with whole numbers,
- 15:27addition with the decimals, and addition with fractions,
- 15:29for example.
- 15:31And my argument is: it is
- 15:34the same thing. All we are doing is combining quantities of the same size a unit.
- 15:39And so we can use that common language to condense what we're talking about.
- 15:45My students throw things at me after a while 'cause I have tons of dad jokes,
- 15:49but again, this goes back to my grandmother,
- 15:50but: "How do you catch a, a unique rabbit?" "Unique up on it." OK,
- 15:54that was the line. "And how do you catch a tame—
- 15:57That was an impressive dad joke,
- 15:58by the way.
- 15:58I know, I know. ~ And you know,
- 16:00"How do you catch a tame rabbit?" You know,
- 16:02"It's the tame way."
- 16:04And so my argument is adding whole numbers,
- 16:07adding decimals, and adding fractions,
- 16:09it's "the tame" way. We're just combining quantities of the same size of unit.
- 16:14And so we want to condense that language.
- 16:16And part of that language is: There are a couple terms I use
- 16:19are "equal exchanges," which is,
- 16:21to me, just equivalent expressions,
- 16:24but it, it permeates throughout.
- 16:27It's an easy way to think about anybody that's exchanged money
- 16:30can, you know, [exchange] 10 ones for 1 ten-dollar bill,
- 16:33you know, we, we can associate with that.
- 16:34And then there's also the idea later on of what I call "analogous problems."
- 16:38And that is: problems that involve the same quantities,
- 16:42the same actions, but different sizes of units.
- 16:46And again, they permeate through all four operations.
- 16:50So I, I see that throughout.
- 16:53And so, we talk a lot about that communication about discourse,
- 16:58like,
- 16:59again, fractions. You know, students can tell me what the numerator
- 17:02and denominator of a fraction is,
- 17:03but what does it mean? Well, numbers are just stressing this idea that numbers
- 17:09are just a multiplicative tethering of quantities and sizes of units.
- 17:13And once we started talking about that,
- 17:15it just connected for these adult learners who are like,
- 17:17"Oh, my gosh, why didn't nobody ever tell me that?" You know,
- 17:20and so I suppose even with fractions—I,
- 17:22I know we talked about this a little bit—but,
- 17:24like, a fraction like five-eighths.
- 17:25Just to
- 17:28put emphasis on the size of the unit,
- 17:30we talk about five groups of one-eighth.
- 17:32We really want to talk about the quantity,
- 17:34which is how many, and the size of the unit,
- 17:38which is how much.
- 17:39And so that is just a couple examples of where I use that language.
- 17:44And so, for me, you know, in summary,
- 17:46it it's a connector between critical ideas.
- 17:48So I want to back up because I think the addition problem that you,
- 17:52you were talking about with that group of teachers was 34 plus 58.
- 17:55Yeah.
- 17:56And then you were also talking about,
- 17:58as you said, like, 0.34 plus 0.58.
- 18:02Uh-huh.
- 18:03And in my head, I started to think about:
- 18:05Well, what we're really talking about in the first case is:
- 18:093 tens and 4 ones, 5 tens and 8 ones.
- 18:13And so we're [combining]
- 18:15the 3 tens and the 5 tens and the 4 ones and the 8 ones.
- 18:18And then to follow the process through,
- 18:21it's three-tenths and five-tenths,
- 18:23and it's four-hundredths and eight-hundredths.
- 18:25And really, the process we're going through is the same.
- 18:29And there's an equal exchange that happens along the way in both of those processes.
- 18:34Yeah.
- 18:34But the processes themselves stay the same.
- 18:37Yes. Yeah, like with 34 plus 58,
- 18:39you're adding 4 ones and 8 ones together.
- 18:42So you get 12 ones. So you do the ex—equal exchange:
- 18:4510 of those ones is 1 ten. And then with 30 point—I would,
- 18:50I say 0.34 plus 0.58—
- 18:53—you got twelve-hundredths. And so equal exchanging 10 of those hundredths
- 18:58for one-tenth. And so, you know,
- 19:01the equal exchange is happening,
- 19:04but with different sizes of units.
- 19:06Yeah, and I think you made a reference to eighths,
- 19:09and I wanna just name this for listeners in case they missed it.
- 19:12The difference between describing something as five-eighths and—how
- 19:17did you say it?
- 19:18Five groups of one-eighths, one-eighth,
- 19:20I really want to put an emphasis on:
- 19:21We're working with children. They are [having] a hard time distinguishing—you
- 19:26know, that's another thing with the language,
- 19:28you know, the, the, the suffix t-h-s—or the morpheme t-h-s—is you know,
- 19:34it's easy with obviously halves,
- 19:36and thirds is a little problematic.
- 19:38But fourths, fifth, sixth, and sevenths,
- 19:39we can associate that with the partitioning action—
- 19:44you know, fourths is partitioning that unit,
- 19:46whatever that unit is, into four equal pieces;
- 19:48fifths, five equal pieces, ~ or equal lengths.
- 19:53So it's embedded in there. I just don't think we rely enough
- 19:56on it because students—many times,
- 19:57I, I see this happening again and again—students don't hear
- 20:02the difference between, let's see,
- 20:055 eights, as in five groups of 8,
- 20:09and five-eighths, five groups of one-eighth.
- 20:13And so they don't make that distinction many times,
- 20:15but also the emphasis is on: When you say "five-eighths," you're
- 20:19not really—many times we're finding students aren't attending to the size
- 20:22of the unit. But if you describe it as five groups of one-eighth,
- 20:26we've got our unit fraction, which again,
- 20:29everything else builds from that unit fraction.
- 20:31So it's much more explicit and meaningful.
- 20:34And then when we talk about addition of fractions,
- 20:37we need a common denominator because again,
- 20:40addition is about combining quantities of the same size of unit.
- 20:42So,
- 20:43five groups of one-eighth and four groups of one-eighth is nine groups
- 20:46of one-eighth. You know, it just kind of fits.
- 20:49I really appreciate this, Patrick,
- 20:51because this seems so simple a move on the part of the teacher,
- 20:57in the sense that I can control the language choices I'm using when
- 21:02I'm describing quantities or the ways that we're acting on quantities.
- 21:06And that can have a really profound effect on kids' understanding.
- 21:12Absolutely.
- 21:12I think what I'm trying to say is it's very much within my control as a teacher
- 21:18to make those kinds of shifts,
- 21:19but the impact on the other side could really be profound if I can build
- 21:25the habit of using language the ways that you're describing.
- 21:28Yes. Yes indeed. And like you said,
- 21:31I like the idea of not, this is not a monumental shift.
- 21:34I mean, you may start to see mathematics differently as you read the book
- 21:38and some of the ideas—but the shift,
- 21:40these are easy shifts to make.
- 21:42This just more of a little bit of a nudge towards adjustment in language.
- 21:46Before we move from language and talk about "symbolize it," I just want
- 21:50to go back to the phrase "equal exchange." And I'm really taken with this.
- 21:56I heard you on another podcast talk about equal exchange.
- 21:59And I think it also is connected to this idea that you have some pretty meaningful
- 22:06feedback around the kinds of language that we might use with kids.
- 22:10But I wonder if you'd talk about equal exchange and then also how
- 22:13you think about the kind of language we use
- 22:17in math classrooms.
- 22:18I'm gonna put you on the spot here for a second,
- 22:19Michael. I if I have you write down the symbol string 3,
- 22:236, 0, 0, 0, 0,
- 22:26what are you gonna say back to me?
- 22:29So, I want
- 22:29to clarify to make sure I've got it right.
- 22:31If I wrote down 3, 6,
- 22:34and then four 0s afterwards—
- 22:37Yes. You got it. You got it.
- 22:39—what will I say?
- 22:40Yeah.
- 22:40What's occurring to me is: It will take me a moment to think about the magnitude,
- 22:45and I would probably place a comma to help me clarify ~
- 22:51how big this number is. So after doing that,
- 22:55I would say three hundred and sixty thousand.
- 22:59Dead on. So we can all agree that's 360,000,
- 23:02right?
- 23:02We're good with that. OK. What is it 36 of?
- 23:06That same amount would be 36 what?
- 23:09It's 36 ten thousands.
- 23:12OK. Or 3.6 what?
- 23:15Oh, it's 3.6 one hundred thousands.
- 23:19Exactly. And so, again, this is kind of to show the trajectory of where this could
- 23:24go. You have just learned scientific notation.
- 23:27You know, this idea that you've taken 360 and you said "thousand,"
- 23:33so that's 360 times 10 to the third,
- 23:35which is 36 times 10 to the fourth, [or] 3.6 times 10 to the fifth.
- 23:42So as the quantity decreased by a factor of 10,
- 23:47the size of the unit increased by a factor of 10.
- 23:50And so this is an idea, again,
- 23:52of an equal exchange. And so we're,
- 23:54when we're dealing with 10 units of ten—so,
- 23:56for example, 1 ten for 10 ones—I have 10 ones and I'm giving
- 24:02you 1 ten. So the quantity decreased by a factor of 10,
- 24:06but the size of the unit increased by a factor of 10.
- 24:10So there's that reciprocal relationship that happens as we do equal exchanges.
- 24:17And so that happens throughout mathematics.
- 24:19And what's interesting is I was just playing Monopoly one day and I thought,
- 24:22"Oh, my gosh, it's there. It's always been there." You know,
- 24:25where you give the banker 2 ten-dollar bills and they give you 1 twenty-dollar bill.
- 24:31That back-and-forth relationship,
- 24:33that reciprocal relationship between the quantity and size of unit
- 24:36has always been there, which is why they're equal exchanges because
- 24:39the product of that is always going to be one-tenth times 10 is 1,
- 24:44one-half times 2 is, is 1. It's always been there.
- 24:46And so it bridges all the way up through mathematics,
- 24:49starting with elementary school.
- 24:51You know, what's cool about this is:
- 24:52I think initially when I read the term,
- 24:55what I was thinking about was fairly procedural,
- 24:58which is we use language like "carry the 1" or "borrow from the
- 25:026," and that obscures place value.
- 25:05And an equal exchange I think makes what's happening clearer in
- 25:10the form of language. But what I'm really taking away from this now is that part
- 25:15of the
- 25:17outcome is that if you engaged in the kind of tasks or questions that
- 25:21you were describing, you also build a much clearer sense of what "equal" means
- 25:26mathematically, which is a huge benefit for children,
- 25:30particularly as they're moving through elementary school and starting
- 25:34to move into secondary math. And, and so,
- 25:37it's a bit of a two-for-one in the sense that the language clarifies the arithmetic,
- 25:42but it also sets up this understanding of
- 25:44equalness, which really, really pays dividends in secondary.
- 25:48Yeah, 'cause we're we're going to talk about equivalent expressions,
- 25:51numerical, algebraic, equivalent equations,
- 25:53equivalent systems. So there's all this equivalence that happens.
- 25:56I feel—to me this is one of the binding elements.
- 25:59Equivalence is one of those binding concepts that under,
- 26:01underpins mathematics.
- 26:02So I feel like we probably need to move to "symbolize it." And part
- 26:07of what really struck me in the phrase "symbolize it" was "it," meaning you're
- 26:12symbolizing something. It could,
- 26:13I suppose, be an action, a relationship,
- 26:16a visual model, maybe an arrangement of physical materials,
- 26:20even a context. But that symbolizing to me felt like an act of translation.
- 26:26Am I understanding what you're getting at properly?
- 26:29Or is there a different interpretation that I should be thinking about,
- 26:32Patrick?
- 26:33You know, there's a lot of, it's—symbolizing [is] a very broad term,
- 26:36and you know, just by you asking that question has got me reflecting on it a lot.
- 26:40But I think about you know, we write a number,
- 26:42like I said earlier, like 74. We have to share that information.
- 26:46We use the Hindu Arabic description of it to write those numerals down
- 26:50and we talk about it: 7 tens and 4 ones,
- 26:52if that's the context. And so there's always going to be
- 26:55a translation involved because,
- 26:57again, just me communicating what I just said to you is a translation
- 27:01of what was written symbolically.
- 27:03You know, I had to interpret that.
- 27:04And so, to me, symbolizing is always about interpretation.
- 27:08Just last week, I was interviewing a group of fifth graders
- 27:12on the multiplication problem 3 times 7.
- 27:14And what was fascinating to me—again,
- 27:17writing those symbols that we all kind of had shared understanding
- 27:20and what that means. But what they did to communicate their understanding
- 27:24to me was so radical, so many different possibilities.
- 27:27You know, one student drew 3 groups of 7 dots and counted them individually.
- 27:32Another student wrote 14 and 14,
- 27:34and then subtracted 7. And so I had to ask [about it]. [They said,] "Well,
- 27:38that was 2 times 7 and 2 times 7.
- 27:40And then I subtracted one group of 7." And that was just a couple ways that were
- 27:44done. But there were all these ways that when I just flashed this commonly
- 27:48understood symbol string in front of students,
- 27:50it cued something—like I said earlier,
- 27:52that concept image—it just spewed things out of each mind,
- 27:56and they were radically different depending on the student.
- 27:58And so that aspect
- 28:00is the dynamic part of symbolizing to me is that students can come at
- 28:05it from so many different perspectives.
- 28:06And the beauty of teaching is,
- 28:07first of all, I've got to communicate clearly what 7 and 4 actually represents when
- 28:13it's a string, and talk about the meaning of that and why.
- 28:16But also, as a teacher, when I let my students loose and they start interpreting
- 28:21the symbols I use, I have to navigate the terrain of trying to put
- 28:25all those pieces together. To me,
- 28:27that's the beauty of teaching.
- 28:28I love taking
- 28:29what my students say and try to mold something beautiful with it.
- 28:32That's when it's fun for me.
- 28:34I 100% agree with you. It's interesting,
- 28:36the way you describe that as a symbol string (chuckles)—7 times 3 is
- 28:40a string of symbols put together—and understanding what the meaning of that is,
- 28:46that's a special sauce in—
- 28:48—in teaching and also in learning.
- 28:49It can also be the thing that scares the heck out of folks because—
- 28:53—there's maybe a loss of control or creating space for kids
- 28:57to share their thinking. And I think you put your finger on something that
- 29:01can either be incredibly exciting
- 29:03or nerve-racking for a lot of folks.
- 29:06I think a lot about this where we pose a symbol string in front of students:
- 29:09"3 X 7" or whatever, "3 dot 7." And we kind of impose that meaning on them,
- 29:14but we we don't give them a language,
- 29:16and just say, "OK, this is multiplication." And depending on which country
- 29:20you come from, this is interpreted differently.
- 29:21But the first numeral in a multiplication problem I interpret as a quantity.
- 29:25And the second is the 7—like,
- 29:28in 3 times 7—is a multiplicative unit.
- 29:31So it is a unit. It's like, "We have 3 sevens,"
- 29:35you know; we commonly use the term.
- 29:36So there's a lot that goes into that that when I'm teaching that,
- 29:40I want to make clear how I want the students to interpret that symbol string,
- 29:44but the way they communicate their understanding of that symbol string
- 29:48can be very diverse depending on their own understandings.
- 29:51I think part of what jumps out for me too is by offering the chance
- 29:54to communicate their understanding of that symbol string,
- 29:57it really is a formative opportunity for you because you get a sense
- 30:01of what's going on in the room,
- 30:03like how are they thinking? And then doing that allows you to connect where
- 30:08you want them to get to with where they are right now.
- 30:10Whereas if you forego the opportunity to offer them the opportunity to make sense
- 30:15of it, you don't know if you're tethering to something they understand
- 30:19and working from there,
- 30:21or if it just absolutely went over their heads because it wasn't
- 30:25in any way connected to their understanding.
- 30:27And so I think there's a sense of maybe loss of control that comes along with giving
- 30:32kids that opportunity, but it also pays dividends because once you know
- 30:36how they're thinking, you can game-plan much more effectively as a teacher.
- 30:40The risk is giving up control,
- 30:42but the reward is what you gain because now you understand your kids better
- 30:46and you can make moves more effectively.
- 30:48Yeah, I tell people all the time:
- 30:50I've been in education now for 34 years,
- 30:52and for the first 20 I felt like I was pretty stagnant in my teaching.
- 30:56I'd learn a few things, get a few things better,
- 30:58but I felt like my teaching improved exponentially when I just started listening
- 31:02to my students. And I'm like, ~ "Oh, they don't really understand that
- 31:06the way I thought they would. And OK,
- 31:07so now I can modify and I can latch on to what they're telling me as opposed
- 31:11to just me thinking, "This is what's going to be best."
- 31:14You know, that's I think a really great segue because we've been dancing around
- 31:18the edges of my next question,
- 31:20which is: How do you think about the role of an elementary teacher in symbolizing?
- 31:25Like, is their role to show or to tell?
- 31:28Is their role to pull students' ideas and then offer a symbolic model for that?
- 31:35Are those two things in relationship with one another?
- 31:39Or is there another way to think about the teacher's job when it comes to
- 31:43symbolizing either the things that kids are saying or the things they're describing
- 31:47or the things that they're seeing?
- 31:49It's twofold. It's using precise language to communicate their understanding
- 31:52of ideas. You know, a lot of times there's hidden mathematics between what we're
- 31:57doing. As I've said with the number 74:
- 31:59What base am I operating in? But that's kind of hidden.
- 32:03And then it it really is this is the secret sauce of teaching.
- 32:07When you set students loose and you give them a problem—I know we've talked
- 32:10a lot about contextualized problems;
- 32:12I'm a believer in contextualized problems,
- 32:14but—that's where you kind of start to see
- 32:17the different ways that our students are understanding ideas.
- 32:19You know, that student, for example,
- 32:21I said earlier, who drew out an array of 7 by 3 to communicate
- 32:25her understanding multiplication,
- 32:26that's great that she could create the represent the model,
- 32:28but then she counted by ones. And so that tells me we're probably not ready
- 32:34to be thinking about multiplication.
- 32:35We need to start thinking about grouping at a,
- 32:38at a, a little bit higher level.
- 32:39So we need to start building that understanding.
- 32:42So it really ~ provides teachers a lens
- 32:46with scaffolding their instruction.
- 32:47And without that, we're just kinda throwing darts hoping something hits.
- 32:51I wanna touch on one other piece before we close,
- 32:54Patrick. Another piece that I really liked about the book is:
- 32:57You were really taking pains to help teachers see that there's connections between
- 33:02what's happening at different grade levels.
- 33:04And an equal exchange is an example of that.
- 33:07One of the things that I've heard you say is:
- 33:09The action remains the same; it's the size of the unit that changes.
- 33:12And I wonder if you could be a little bit explicit about,
- 33:15like, where are some examples of that in elementary mathematics that
- 33:20would help someone who is a lower-grade kindergarten,
- 33:23first, second grade teacher recognize how what they're doing continues;
- 33:28it's just continuing with a different unit size.
- 33:31~ Or vice versa, thinking about,
- 33:33like, if I'm a third or fourth grade teacher,
- 33:36where's the connection to what's happening in younger grades?
- 33:39Great question. I love it. Thank you for asking it.
- 33:42Let's start out with just 4 plus 8.
- 33:44You know, there's something monumental that happens at 10.
- 33:47That's a new unit. So again, even though it's easy to count 8,
- 33:529, 10, 11, 12, there's that idea of an equal exchange that happens right at 10.
- 33:57That's the first one. So I love the base ten blocks a little bit later,
- 34:00but the 10-frame. [The] 10-frame is such a neat tool to start to develop that idea
- 34:05of making a ten.
- 34:06So we've got, you know, kindergarten,
- 34:08first grade, we're in that. And then we go to two digits.
- 34:10And again, problems like—I, I've been using,
- 34:13I think 34 plus 58 quite a few times here,
- 34:16so I'll stick with it. But 34 plus 58,
- 34:19340 plus 580, 3.4 plus 5.8,
- 34:24we could go on and on and on, but those are what I call analogous problems.
- 34:28And so that's a connector, you know,
- 34:30because again, addition about combining quantities the same size a unit.
- 34:34So the goal is to be consistent with that language all the way through.
- 34:37And so we can make those connections between what we do with single-digit addition
- 34:42to what we do with 2-digit addition to moving into decimals and fractions
- 34:46all the way up the frame.
- 34:47And the same is true with multiplication.
- 34:49You know, 6 times 8 is 48. And we don't really think about it [in this way],
- 34:52but it's 48 ones. That's the unit that's associated with it.
- 34:55But we could also think of that as 4 tens and 8 ones.
- 34:58But then we have 6 times 80, 6 times eight-tenths,
- 35:006 times 8,000, 6 times eight-fifths.
- 35:04We still have 48 of something.
- 35:06Whether it's 48 tens, 48 hundreds,
- 35:0948 thousandths, we still have 48 of something.
- 35:13Forty-eight fifths, problems with fifths is the regrouping happens at five,
- 35:17not at ten. So our equal exchange involves five-fifths for a whole unit.
- 35:22So that's a distinction, but you're still taking six-eighth of a different unit.
- 35:27So your result's gonna be 48 of something.
- 35:29And that's the same with division.
- 35:31You know, like I I think about,
- 35:33for example, 24 divided by 2 and 8 divided by two-thirds.
- 35:37When you first look at those problems,
- 35:39you think, "There is no connection whatsoever." But when you put those
- 35:42in context and students start modeling,
- 35:44but let's say you have 24 peanut butter and jelly sandwiches and you're going
- 35:48to give each person 2 peanut butter and jelly sandwiches.
- 35:50Well, you're going to go through that whole process and you're going
- 35:53to create 12 groups of 2. Well,
- 35:55let's say it's 8 peanut butter and jelly sandwiches and you're going
- 35:58to give two-thirds of a peanut butter-jelly sandwich to each person.
- 36:01How many people can you give
- 36:03two-thirds of a peanut butter-jelly sandwich to?
- 36:05Again, when you create that 8 and you create the partitioning to make thirds,
- 36:09you have done an equal exchange.
- 36:11You've changed 8 ones to 24 thirds.
- 36:13So now, how many groups of two-thirds are in twenty-four thirds?
- 36:17Well, it's going to be 12. 12 of what?
- 36:1912 groups of two-thirds. So again,
- 36:23it's the same activities and the same quantities,
- 36:27but on a different size of unit.
- 36:29So it goes back to my silly joke about
- 36:32the tame way again. But it it is.
- 36:33There there's a structure that fits throughout mathematics
- 36:37and it's not compartmentalized.
- 36:38It fits together. And the key is to help our students understand where those places
- 36:43are.
- 36:44What you make me think is how much of elementary mathematics is about units
- 36:48and unit exchange and recognizing equivalence between quantities of units
- 36:54and other units. It's pretty powerful.
- 36:57And I think what I love about it is:
- 36:58It does help you see that there's a long journey that's going on,
- 37:03but the themes of that journey continue to come back and show themselves
- 37:08in slightly different ways.
- 37:10I 100% agree. I think it's so amazing to me that to me units are a huge deal,
- 37:15but with addition they're hidden behind place value.
- 37:19With fractions they're in the denominator written as a numeral many times,
- 37:22which students have already associated as being a quantity because everything
- 37:26they've done with whole numbers has involved the numeral representing a quantity.
- 37:30And the only time in mathematics [...] where a numeral represents a size
- 37:35of unit is in, when it's a fraction.
- 37:37And so that is a huge disruption
- 37:39for me, and so, that needs to be,
- 37:41you know—total, completely agree.
- 37:43You know, I think this is actually a pretty good pivot point because we talked
- 37:48a lot about, kind of, the big ideas in See It,
- 37:52Say It, Symbolize It, I wonder if you could talk about how someone who's listening
- 37:57to this and wants to keep learning,
- 37:59~ how might they continue to dig in either by contacting you or
- 38:04by engaging with content that you've put together?
- 38:07See it, say it, symbolize it. It's on Amazon,
- 38:09and it's also on Solution Tree.
- 38:11And my website, it's still a work in progress,
- 38:15but it's called: unleashingmathematicalbrilliance.com.
- 38:15And I'm continuing to put ideas up there.
- 38:19I have some graphic organizers related to what I call superpower understandings
- 38:24on there, as well as a few other podcasts I've done and and a few blog entries
- 38:28as well that I'm continuing to build on.
- 38:30But just trying to build more resources to support teachers because what
- 38:34I hear often is:
- 38:36"I love the ideas, but how do I fit this into my curricula?" And
- 38:40so many times there's nothing there.
- 38:42Yeah. And I will say for listeners,
- 38:44we will add links to all of the resources that Patrick talked about.
- 38:48I could keep going, Patrick, but I think this is probably a really good place
- 38:51to stop. I just want to thank you again for joining us and
- 38:55for a lovely conversation. ~ Thanks so much for being a part of the podcast.
- 38:59It was my pleasure. Like I said,
- 39:01a huge shout-out to all the work that you guys do.
- 39:03I fell into that work 25 years ago of all the work happening at
- 39:06the Math Learning Center. And I've just been a huge fan of all the work that
- 39:10you guys do there.
- 39:11Ah, thank you so much.
- 39:13And thank you, our audience, for listening.
- 39:16We'd love to hear what you all think.
- 39:18Is there a Grandma Edna in your life who helped you understand new math concepts?
- 39:22How have you used the ideas from See It,
- 39:25Say It, Symbolize It in your teaching practice?
- 39:28Getting in touch with us is easy.
- 39:30Just head over to mathlearningcenter.org/podcast and fill out the contact form.
- 39:37This podcast is brought to you by The Math Learning Center
- 39:40and the Maier Math Foundation,
- 39:42dedicated to inspiring and enabling all individuals to discover their mathematical
- 39:48confidence and ability.