The Reasoning Behind the Common Core

The common core has been famously skewed, lampooned, and criticized by comics, parents, teachers, and the like. But, there's a really solid method to the madness, one that I can much appreciate as someone who teaches a math related subject.

Over at Vox, Libby Nelson explains how the Common Core curriculum for math aims to help kids gain a sense of how numbers work and the underlying structure of mathematics. The goal is for kids to understand why they do A and B to get C, and not just that they need to do A and B to get C.

Take this famous problem skewed by Colbert:

The idea behind using a number line for subtraction is that students get a visual representation of what subtraction is: figuring out the "distance" between two numbers.

  • Students put the two numbers at opposite ends of the number lin
  • Then they travel from one number to the next to figure out the distance. It's 4 steps from 316 to 320, 100 steps from 320 to 420, 7 steps from 420 to 427.
  • Then they add the steps together: 4 + 100 + 7 = a distance of 111.

This resonated really strongly with me because I always get out the number line to teach for loops for much the same reason. My students sometimes seem to actively resist trying to learn how to reason about code, instead very much preferring to just learn what syntax they need to throw at a problem to get the right answer. This, of course, does not yield particularly good code.


She leaves off with a common problem with teaching, and that's that sometimes the teachers don't know how to teach the new methods, and neither do the parents who are trying to help heir kids. So the conceptual theory gets watered down to a new set of steps to solve the problem, and we're back to the problems the common core is trying to fix.

"What we want to tell parents to do is they don't need to teach the math," says Briars, the president of the National Council of Teachers of Mathematics. "What they need to help their children do is figure out, What is the problem asking you?"

I relate to this so so much because my students keep going to these awful tutors. Upper classmen who have to tutor for service credit, but aren't very good at programming and even worse at the conceptual underpinnings. And so, instead of helping them problem solve, they inadvertently do the problems for them, and usually in the most wonky way possible.


So here's to hoping that teachers sort out how to teach common core and that parents sort out how to help with problem solving instead of just solving the problem, 'cause it'll be really interesting to work with students and coders who've had a solid education centered around understanding math rather than just doing it.