# The Elusive Relationship of x & y

“Ali has \$10 dollars and spends \$5 dollars every 2 days.” That was the simple scenario offered for the linear relationship that my students were working with at the time. I was having them write equations from various contexts in order to emphasize the concepts of slope and y-intercept. Boy, did I unravel a serious issue.

Typically, what is asked when dealing with slope-intercept form of lines is somemthing like: “What is the slope and y-intercept of the following equation:  y = -(5/2)x + 10?” Then those values are to be used to graph the equation. The hope commonly is that the students have been paying enough attention to know that the “slope is the number in front of the x.” The frustration commonly is that students still can’t identify the slope from the equation. From a context, the slope is even more difficult to identify, like with the Ali Scenario above. What I found out through a very unique question is why it is so difficult for them.

In the previous contexts that I had offered them, the students would see only two numbers. “Sally has 1 friend and makes 2 new friends every week,” as an example. I was asking them to identify the constant and the rate of change in examples like this. That was a struggle, but they eventually started to get it. When they ran across the Ali Scenaro, I was expecting the three numbers that were representing only two values to cause issues. I was correct. But it was their response to my next question that opened my eyes: “What two quantities are related here?”

I got blank stares. So I asked them to write down the two words that represent the quantities being related in the given context. When I looked at their answers, I was shocked to find the two words that over half the class had written down: spend & has!

Really?! I wrote those two words on the board, and asked them, “Does it make sense that the number of spends that I have determines the number of ‘hasses’ that I have?” I noticed everyone’s attention in class was riveted on the two words on the board. They knew what I was saying didn’t make sense, but they were struggling to reconcile the issue, so I asked another question. “What determines what in this scenario?’ A student finally offered, “days determines dollars.” Yes!

We had to wrap up the day, since I had spent so much of the period mining this one context for mathematical understanding. So the next day, I started the lesson by posting the same Ali Scenario and the two sets of words, “spends & has” and “days & dollars.” We revisited the idea that even though the sentence claims that “Ali spends and Ali has,” we are looking for words that represent numbers. Then we can use those numbers and a few symbols (variables, operations and equal sign), to write an equation (an abstract generalization) to represent the relationship. That equation (like the scenario and eventually the graph) represents an infinite number of combinations of “days & dollars.”

The students now easily identified 10 as the constant and wrote it properly as the y-intercept of the equation. The trouble was in dealing with a slope that was represented by a negative fraction, which was the issue that I originally intended the scenario to pose. However, my adventure into the minds of my Algebra students helped remind me that we too often have them leap from the concrete to the abstract, or that we skip the concrete altogether. How many of the millions of Algebra students in this country are graphing linear equations, yet have no idea that x and y actually represent a quantitative relationship? Focusing on getting the answer correct (“Graph this by starting at this number and counting up and over this number.”) often times bypasses the ultimate goal: mathematical understanding.

# First Day Challenge (cont’d) – The 6 C’s

Hopefully, my challenge pressed you to create a new and unique First Day routine. As I shared in my previous post, I was inspired by the story of the martial art student who claimed that for each good teacher he had in China, all the principles that he would master with them were taught in the very first lesson. So I came up with the 6 C’s of the Math Mission. These are basically my answer to the question “Why should we learn this?”

1. Conceptual Understanding of mathematical principles and demonstration of Procedural Fluency,
2. Critical Thinking in a mathematical context,
3. Communicating Reasoning in a technical field,
4. Constructing Models of the natural world,
5. Creativity expressed freely and joyfully in the problem solving process,
6. Collaboration with others.

At the beginning of my first day with the students, I have them take a  4-question Opening Quiz. Each question is headed by and supports one of the first four of the 6 C’s above, which are the criteria for our state test. I have the students take the quiz with the explanation that it is like a movie trailer. Rather than a test on something I hoped they learned last year, the quiz is a  preview of coming attractions. Therefore, I don’t expect them to be able to answer all four questions; however, I do expect them to give an intelligent response. I preach to them that we cannot always give a complete response or even an accurate response, but we can always, always always give an intelligent response. Showing numbers, equations or diagrams is intelligent; leaving the paper blank or writing ‘idk’ is not.

The students work independently for a few minutes while I do the normal housekeeping duties, like checking their course schedules and adding students to the roster. Then I have them share ideas with each other. If they like what they see on someone else’s paper, they are free to write it on their own as long as the person explains it to them. “We share; we don’t copy.”

Then comes the time for a whole class discussion. I use this opportunity to inform the students that this process of independent thought, group sharing and class discourse  (think, pair, share) is a normal routine in the class. I point out that the 6 C’s are displayed on the front wall, because this is what I come to work to do each day (my goal). I am not there to get them a good grade (their goal). Of course, if I achieve my goal, they will achieve theirs. So I ask  for volunteers on each of the questions, stressing the appropriate meaning for each of the 6 C’s:

The second half of the period is committed to getting to know the students. We start with the first student who stands up, states their name and something interesting about themselves. The statement of interest is really just a stall tactic so that I can review the names that have already been mentioned. After every student has done this, I go back and state all their names. And finish the intros with some brief information about myself.

I close the class by telling them that the order of things today was intentional and symbolic. That the class will be about math first and foremost (not points and homework), and of course, it is each one of them to whom I must teach math, so they are important as well. I reiterate some of the points of the class culture like giving an intelligent response, think-pair-share, and “share, don’t copy.” I hand them the grading policy as they leave. We will discuss each of its points when the time comes. Hopefully, I communicate everything in a dynamic manner so the students anticipate a fun year full of learning.

# First Day Challenge

The first day of the new school year is coming up soon for most of us. While the annual tradition of handing out the syllabus and grading policies will be very tempting, I challenge everyone to treat the first day for the opportunity that it is … A chance to make a lasting first impression about who we are and what they are going to learn. If we talk to them about classroom rules, then the rest of the year instantly becomes about playing school in order to collect enough points. If we talk enthusiastically about math, then the anticipated year is seen as a passionate quest to learn.

I got this idea for the new first day routine from a story I read about an American martial artist who toured fighting schools in China. He said that for all the good teachers, he learned everything they were going to teach him in the first lesson, and the rest of his time with them was spent mastering those first-day lessons.

So I asked myself, what is it that I want to communicate to my students that would embody an entire year’s worth of learning in one day? I came up with the 6 C’s of the Math Mission.

1. Conceptual Understanding of mathematical principles and demonstration of Procedural Fluency,
2. Critical Thinking in a mathematical context,
3. Communicating Reasoning in a technical field,
4. Constructing Models of the natural world,
5. Creativity expressed freely and joyfully in the problem solving process,
6. Collaboration with others.

My first day with students is this week. I will share then what I do with my 6 C’s introduction. In the meantime, I encourage you to think about what your new first day ritual may look like.

# The 4-1/2 Principles of Quality Math Instruction

Imagine a small box with an American flag painted on each side. This represents the box in which we American teachers think about education … how we view the role of the teacher, the nature of the learner and the purpose of school. I say this, because ongoing international research studies show that teaching is a cultural phenomenon. We do not teach the way we were trained to teach; we teach the way we were taught. While there are differences among us American teachers, there are glaring commonalities that we uniquely share. The same can be said for our counterparts abroad. We could make a similar box and cover it with French flags and have a conversation about how French teachers think about education. We could do the same for the Japanese or any country for that matter. The issue is that while our education system has a few great things to share with world, for the most part, countries which outperform us in academic math tests do so because their box is far superior to ours.

That lesson can be found in the Trends in International Mathematics and Science Study (TIMSS). In March of 1998, The Math Projects Journal was granted an interview with Dr. William Schmidt, the American Coordinator of TIMSS. He claims that among the top-performing countries in mathematics (no, the United States is not one of them) there is no common methodology, but there are common principles of instruction that all the top-performing countries share: teaching to conceptual understanding and teaching with mathematical substance. In his writings and public presentations he stresses two additional components: standards and accountability.

Therefore, I have consolidated these findings into what I have dubbed “The Four and a Half Principles of Quality Math Instruction,” or in the vernacular of the digital age, “Q.M.I. version 4.5.” The first four principles come from the research shown in the international comparisons of the TIMSS report:

1) STANDARDS: Focus on a the limited number of topics that your students need to know; don’t just cover the textbook.
2) CONCEPTS: Teach students to understand what they are doing, not just to mimic what you are doing.
3) SUBSTANCE: Intellectually challenge students; raise your level of questioning.
4) ACCOUNTABILITY: Hold students to knowledge and performance expectations that go beyond grades and unit credit.

The fifth principle comes from professional experience and opinion rather than research, and therefore, its emphasis is demoted to a half-principle.

½) RAPPORT: No philosophy, technique, methodology, instructional material or textbook can replace the student-teacher relationship. You must reach ‘em before you teach ‘em.

Since I don’t have a PhD after my name, I found backup from someone who does. I was reading a book titled Six Easy Pieces by Dr. Richard Feynman. It caught my eye because the subtitle of the book was, “Physics Taught by its Most Brilliant Teacher.”  The preface of Six Easy Pieces is full of insights into the teaching philosophies and methods of one of the finest teachers of arguably the most difficult subject in contemporary academia. Here are some quotes by Dr. Feynman regarding teaching:

Dr. Feynman on Standards:

First figure out why you want the students to learn the subject and what you want them to know, and the method will result more or less by common sense.

Dr. Feynman on Concepts:

I wanted to take care of the fellow who cannot be expected to learn most of the material in the lecture at all. I wanted there to be at least a central core or backbone of material which he could get…the central and most direct features.

Dr. Feynman on Rapport:

The best teaching can be done only when there is a direct individual relationship between a student and a good teacher — a situation in which the student discusses the ideas, thinks about the things, and talks about the things. It’s impossible to learn very much by simply sitting in a lecture, or even by simply doing problems that are assigned.

So where is “the use of math projects” in the list? Math projects are not on the list, because in-and-of themselves they are not critical to quality math instruction. Projects are effective tools of instruction only when they embody these four and a half basic principles of teaching discussed herein — in particular, teaching to conceptual understanding and with mathematical substance. To gain further verification of the potential effectiveness of math projects, though, I once again call upon Dr. Feynman.

Dr. Feynman on Projects:

I think one way we could help the students more would be by putting more hard work into developing a set of problems which would elucidate some of the ideas in the lectures. Problems give a good opportunity to fill out the material of the lectures and make more realistic, more complete, and more settled in the mind the ideas that have been exposed.

Thank you, Dr. Feynman, for the encouragement to keep creating and implementing quality math lessons and problems, and to persist in developing good student-teacher relationships. Thank you, Dr. Schmidt, for revealing to us the value in teaching to conceptual understanding and with mathematical substance, and for pressing us to see the need for standards and accountability. May we all keep in mind the most important lesson offered by these studies: The greatest determining factor in the quality of the education that a student receives is the decisions that a teacher makes on a daily basis!

# Ultimate Cosmic Power in an Itty-Bitty Thinking Space

“Give me any combination of two numbers that have a sum of seven,” I said to my students. One person offered, “Two, five,” which I wrote on the board as (2, 5). I asked for a few more and got (5, 2), (1, 6) and (0, 7).

“Good,” I praised, “now give me ALL the combinations of two numbers that have a sum of seven.” They chuckled. “I want them all, and I want you to write them down.” The students were hesitant, because they knew there are an infinite number of pairs that have a sum of seven. So I challenged one of them to a race. “You write them down on your paper, I’ll write them on the board. Nobody goes to lunch, until one of us is done. Ready, Go!” I scribbled on the board x + y = 7. “Done!”

They didn’t buy it. “I have just written ALL the combinations of two numbers that have a sum of seven. Since you don’t believe me, I’ll do it a different way. In fact, I’ll take you all on. All of you write down combinations of numbers, that way you get done in one-thirtieth of the time, and I’ll still woop ya. Ready, Go!” I quickly sketched the graph of x + y = 7. “Done!”

This goofy little exercise was intended to impart the idea that mathematics gives us the ability to represent an infinite number of elements in a finite time with little effort. I spread my arms wide in front of the class and exclaimed “Ultimate cosmic power…” then brought my hands to rest on a student’s head and continued, “…in an itty-bitty thinking space.” (A play on the Genie’s words from the Disney movie Aladdin.) No offense to the student, but our brains are not very big. Yet, we were able to take all the pairs of numbers whose sum is seven, shove them all in our heads at once and think about them all at the same time. The ability to then communicate them to the world outside of our heads using equations and graphs is what makes mathematics the Ultimate Cosmic Power.

However, most people don’t share in our awe of this power. I believe that is because we never initiate them into our mathematical club. We keep students on the other side of the room while they watch us speak club code and give the secret club handshake, but we never let them in. I have proof of this …

### Thoughts on Math by the Uninitiated

From an Algebra 2 student who was just kidding, but his joke reflects how many people perceive the purpose of math:

Algebra would be a lot easier if they just told you what x was.
– Scott, Class of ’94

For a moment, I thought this next one was kind of cute when a student had just simplified 3x + 2x to equal 5x:

Only in math do you put two things together and get a smaller thing.
– Neal, Class of ’99

Then I realized … In math we don’t combine to make a smaller thing; we combine to make an equal thing!

Then there was the English Teacher who stopped me in the hallway one day, visibly irritated, and poking me in the chest:

You math teachers aren’t very good. My whole life you have been asking people to find x. Why can’t you find it yourselves?

I don’t know what set her off on that day, but I do know one thing about the three people who made the statements above. They all see the sole purpose of math as a cognitive Easter egg hunt. They close their eyes, while the teacher hides the variable. Ready, set, go. Praises and smiles when the basket is full.

They have no appreciation for the true beauty and power of Algebra, because we never initiated them into the club. So how do we teach them the secret handshake?

## The Initiation Rites

• Context
• Multiple Representations
• Complexity
• Abstract Generalizations

## Context

Too often we jump straight to the naked math problem. For example,  we ask students to graph y = 2x + 1 or evaluate 2 – 5, without offering any kind of context. Context gives the students something to cognitively hold onto while they are grappling with the math concepts. Take for instance, the teaching of negative integers. In the Wallflowers lesson, students are asked to mathematically represent scenarios that they can relate to (a high school dance). While these scenarios are a bit contrived (girls are positive and boys are negative), students can “see” how a balance of positives and negatives equals zero, taking away negatives leaves behind positives, etc. From here it is useful to go to other contexts that are more applicable. The Postman Always Ring Twice relates positive values to checks and negative numbers to bills, showing how truly “subtracting a negative is the same as adding a positive.” By presenting the context first and then asking the students to represent it symbolically, we give them a framework in which to think when eventually presented with the naked math problem.

## Multiple Representations

### Thoughts on Math by One of the Initiated

I once met a Calculus teacher in Massachusetts who was originally from India. She was very distraught about teaching in America, She said that she kept getting complaints from both students and parents about her teaching style. She said that all she was doing was teaching the way they do in India. When I asked her to characterize the style for me, she said that in India there is a saying:

If you know how to do one problem inside and out, you can do a hundred just like it.
– Seheti, Math Teacher from India

I could easily see the contrast. In India they teach students a hundred ways to do one problem. In America we teach one way to do a hundred problems.

To further make Seheti’s point, I had a conversation with my daughter’s third grade teacher on this very point. She asked me:

### Thoughts on Math by the Uninitiated

How would you do this problem?
3,165
-2,987

Of course, she gave me this example because it requires multiple borrowing in a traditional algorithm. I told her, however, that I don’t see it as a subtraction problem; I see it as an addition problem. I have 165 above 3,000 and 13 below 3, 000, therefore, 165 plus 10 plus 3 was 178 … with no borrowing. Her response was, “But why would you go through all that trouble?” I chuckled at the unintentional irony, placed the pencil on the paper and challenged, ” Do your method without picking up the pencil.”

These examples show the strength in teaching students Multiple Representations of a problem, and the weakness of teaching only one method. In the Candy Bars lesson, multi-link cubes are used to demonstrate why we need a common denominator when adding fractions. Fractions, after all, are merely relations to the whole. Operations on fractions can only be done then on the same size whole!

When students are first asked to show one-half of a candy bar with the cubes they put together two cubes of different colors. When asked to “build” two-thirds of a candy bar with the cubes, the construct a stick of three cubes, one being of a different color. When prompted to “show” what fraction of the candy bar they have if they are given portions, they naturally connect the two to make one, which shows two-fifths, which is exactly how they incorrectly complete the algorithm for adding fractions: they add both numerators and denominators.

When corrected and told that the bars must be the same size and still show one-half and two-thirds, the students independently build sticks of 6 cubes each (three of one are colored, two of the other are colored). When then pressed to now tell us how much “of the same size candy bar they now have, they combine the colored cubes, but keep the stick the same 6-cube length and present … five-sixths, which is correct. Publically generating an algorithm that now represents what we do is easy, and the cubes offer a model for students to fall back on in the event that they forget the procedure.

## Complexity

Too often we think that our job is to always make math simple for our students. This initiative then leads us to break problems down to their tiny, separate parts, and we never ask the students to put it all together. This point was made by Tad Watanabe in NCTM’s Mathematics Teacher (Vol 93, No 1, p 31). Mr. Watanabe showed a high school entrance exam from Japan. It had only 7 problems. One of them is displayed on the right. (Click to enlarge the image.)

Take some time to do the above problem. It puts to shame what we expect from our 8th graders: “There are 10 marbles in the box. 3 are red. What is the probability of drawing a red marble?” The Japanese expect there students to do complex problems, therefore, they teach them to do complex problems. We Americans often feel that we have failed if we pose students with difficult problems. One would have to look long and far to find an Algebra final exam in the United States with the level of complexity of the Japanese example above. It is not that Japanese students are more capable than American students and therefore, they can do these kinds of problems. The Japanese students are more capable because they are regularly asked to do these kind of problems!

To further the point on Complexity, I would like to share the story of the American math teacher who visited schools in Bulgaria. When asked to contrast math education between Europe and the U.S., he said he could do so by showing a typical question from both countries:

Typical Geometry Question in Bulgaria: Draw a triangle. Draw a semicircle on each side. Within each semicircle , inscribe the rectangle of the greatest area. Draw the lines that pass through the centers perpendicular to the side of the triangle. Prove that these lines are concurrent.

Typical Geometry Question in America: Draw a triangle.

## Abstract Generalizations

Finally, the ultimate in Ultimate Cosmic Power: Abstract Generalizations. In other words, students are asked to model their world mathematically. As when I ask my daughter and her friend when they were in third grade, “Your class has 20 students. How many are boys and how many are girls ? How many boys and girls might be in another class of 20 students?” We went through several scenarios, and then I asked, “If we allow b to represent the number of boys, and g to represent the number of girls in a class of 20 students, what would you say about the the number of boys, girls and the total students?” They said “b plus a equals 20.” I then showed how to write b + g = 20, and they agreed. There were several abstract representations going on with the girls. Words and an equation, and a brief encounter with data.

The Rising Water lesson does the same thing, but more formally. It first poses a context in words (one representation): A swimming pool contains water 10 cm deep. The water is rising 3 cm per minute. The students are to then generate a table of values, an equation and a graph for this scenario (3 more representations). The objective of the lesson is to teach students that all four representations describe the same relationship between two quantities (time and water depth). The students are then asked to generate their own scenarios, with the four representations. The more that students are asked to create their own models, the better capable they will be when they are presented with one.

So our Initiation Rites into our math club are these four components of Ultimate Cosmic Power (Context, Multiple Representations, Complexity and Abstract Generalizations). We will go back to these constantly in our discussions, as well as to the Four and a Half Principles of Quality Math Instruction posted previously. To show that there is hope in teaching in this manner, I share with you a statement from a former student at the end of the year.

### Thoughts on Math by One of the Initiated

Poetry is the language of love. Math is the language of everything else.
– John, Class of ’99