Betweenness and non-betweenness: absolute value inequalities and Patrick Callahan

I felt a little nervous about having Patrick Callahan come to observe my classroom yesterday, but in the end, it was fun. I had asked one of our security guards, to bring him down to my room when he arrived at our school. He walked in as he always does, all mathematical open-mindedness and pedagogical curiosity.

And we got started.

I felt anxious about having him observe my conceptual lessons about betweenness and non-betweenness. I have never seen anything even close to how I understand and talk about absolute value and inequalities. I talk about boundary points and betweenness and I have students hold up their fists and point their thumbs to show me their understanding. “Is this a situation of betweenness — or NON-betweenness?” I demonstrate with my own fists, swinging my thumbs inward or outward. “Your fists are the boundary points and your thumbs are how you shade your graph on the number line. So is this a situation of betweenness... or NON-betweenness?”

If it is a situation of "betweenness," then students point their thumbs inward towards each other, touching the tips together. If it is NON-betweenness, then they point their thumbs outward in either direction, like a group of indecisive hitchhikers. And once we have done this analysis, then we can do whatever calculations we may need to find our boundary points.

So much of advanced algebra and precalculus depends on having this kind of deep conceptual understanding and thinking. Am I looking for quantities that are GREATER than...? or LESS than? Is this quantity going to be positive? or negative?

For me, the whole thing is intimately hooked together with the real number line. And with number sense. 

When we started last week, we began with an inquiry into “more than” and “less than” and widened our thinking outward from there.We connected more than and less than to number line thinking. I always emphasize Number-Line-Order and Number-Line-Thinking in my Algebra 1 classes. If they think about the number line, then they can anchor their thoughts in their bodies. LHS (or Left-Hand Side) and RHS (Right-Hand-Side) are fundamental ways of thinking in algebra. These ideas are eternal and unchanging. The number line is the foundation of everything. It gives you the “true north” of the real number system.

So we always ground our thinking in our bodies. I ask, “Left Hand Side or Right Hand Side?” “Is this a situation of betweenness or non-betweenness?” “OK, now that we know that, now what?”

I also anchor this unit in what they know about logical reasoning. They have an intuitive sense of how many possible cases a situation may present. I've been a huge Yogi Berra philosophy fan all my life, so I believe that when you come to a fork in the road, you should take it. When you come to a fork in the road, you can go left or you can go right. Or you can stay right where you are. Three possible cases. Over and over I ask them, “What’s going on here? How do you know?”

Absolute value inequalities are either situations of betweenness or situations of non-betweenness. Figure that out and then everything else will run smoothly. Then all you have to do is to use what you already know.

Once students have gotten that figured out, it’s just one more small step to combining their new knowledge with their existing knowledge. Follow the order of operations and common sense. Plus everything you know about the real number line and multiple representations. Then things can naturally unfold the right way.

But I always come back to number sense to what we know about the real number line. Numbers are the ground, the foundation.

So when Patrick walked in yesterday — this world-class mathematician and math education expert — what he encountered was my bootcamp in algebraic thinking. “Hold up your fists! Is this a situtation of betweenness or non-betweenness?”  "How do you know?" And then my waiting until everybody’s thumbs are pointing in the same direction.

It is Logic 101 and numbers and anchoring our thoughts about numbers in our bodies. Like the ancient Greeks and Babylonians and Egyptians before us.

Our next step is to solidify our thinking through what How People Learn calls “deliberate practice with metacognitive awareness.” We are going to do two days of Speed Dating. Now I have to make up Speed Dating cards and a test to use on Thursday. 

And then to document my thinking.

When the class ended, Patrick came up to my tech podium and was excited. He grabbled a whiteboard marker and started sketching and pouring out ideas.

For me, that was the best possible review I could have gotten on this lesson. A five-unicorn review. A direct hit. :)

Stalkers and dreamers

I've talked about this before: there are those who learn by stalking — step by step, one day at a time, one skill at a time, little by little. And then there are dreamers: those of us who try and fail, try and fail, try and fail. Carlos Castañeda makes this distinction between stalkers and dreamers, and it has been a useful distinction for me from the moment I encountered it.

I am a dreamer. I first became aware of this learning pattern when I was about five and learning to ride on two wheels. My dad removed the training wheels from my little red bike and I would practice.

I practiced riding day after day for weeks.

And day after day, for weeks on end, I would fail.

I fell everywhere — on the sidewalk in front of our house, in the driveway, on our block at low-traffic times.

I fell on smooth pavement, on concrete, any time I encountered gravel.

I was frustrated and pretty scuffed up. But in my mind's eye at night, I could imagine riding perfectly.

When I dreamed, I could feel myself rolling smoothly and swiftly on two wheels. In my dream life, I was a person who could ride on two wheels, and I could do so successfully anywhere.

A little less so in my waking life.

I skidded, slid, or toppled over after only a few feet. I still remember how it felt to fall at different moments and on different surfaces. I have a vivid and complete felt sense memory of rolling onto a patch of gravel and sliding to the ground at the intersection of Lenox Road and Hershey. I distinctly remember the feeling of gravel biting into the skin of my knee.

I must have wanted it bad to keep on trying.

Then one day, it just happened.

I had steeled myself yet again for the failure that had become my 'normal,' and I readied myself for more cuts and bruises and wounded ego.

But I didn't fall over.

I was so excited I parked my bike and the garage and rushed inside to tell my mother what had happened. It was the most exhilarating thing I could imagine at the time.

Still, though, I assumed it was a fluke. I continued to prepare myself for further failure.

But then it happened again. And again. And again.

The story of the larva that becomes a butterfly had taken hold of my life. Even after you emerge from the transformation, it takes a while for your awareness to catch up with your changed reality. It took several days before I realized I had stepped into a new normal.

I'd been afraid to hope.

Nowadays I wonder how my students experience transformation from people who believe they can't do math into people who understand that they can. It's hard to trust transformation. As A.H. Almaas says, you've been a larva crawling around all your life, and you believe that the best you can hope for is to crawl faster and to become a bigger, fatter, happier, more successful larva. You see butterflies flying around and you classfy them as anomalies. Most of us never automatically think, gee, that's where *I'm* headed too. Most people think, "Wow those are really interesting beings. I wonder where they come from. I wonder what it would feel like to be one of those."

In math, as in learning to ride a bicycle, it never occurred to me that I could take what I know from other areas of my life to help myself become one of those magical creatures who can ride a bicycle or do math. I did not know it was my birthright to be good and successful at those things. I thought I was destined to remain an earthbound larva.

For a lot of us, it's not enough to say, if you can't do these problems fluently after this investigation, then that means you need to seek out more practice. I needed both experience or discovery and also practice. I needed opportunities for practice and maybe a choice of activities that allowed me to seek out the practice I needed while others were ready for more discovery. Maybe this takes the form of a branching of activities — a practice table and an extensions table, for example. All I know is that students need support and opportunities to self-diagnose and to seek out the experiences they need in that moment. Stalkers need space to stalk further while dreamers need space and time to practice and fall down a lot more.

There is a mystical part of this process that cannot be discounted. 

At times when I feel discouraged about my teaching practice, I have to remind myself about all of this. I feel like I am trying and failing, trying and failing, trying and failing. I have a lot of psychic gravel chewing through the skin on my psychic knees from falling down. I have to remind myself that this is my process.