So math in some ways is like baking. And math used to be taught as a recipe, as
a series of steps you do, and then you get a result.
And what you understand if you’re a cook or a baker is that you add things in certain
proportions for a reason. And that, you know, your cake has to have
this percentage of fats to this percentage of flour in order to work.
And what Common Core tries to do is to do the same thing with math.
Sort of developing what they call “number sense,” and number sense is understanding
more or less why we do the things we do.
Common Core is taught in a way that most people
over 20 don’t recognize. “We find ourselves tearing out our hair at the new math.”
“It’s the same thing I do when I get a check at a restaurant: Draw a bunch of shapes
and tell the waitress to find my error.” “Parents taking to twitter, posting unbelievably
complicated homework assignments.” These math problems circulate that just seem
really nonsensical. Which is really frustrating. If you have a
kid who has this simple problem that looks like it’s being made way too complex for
no reason, it’s totally understandable why people would say: this recipe that I learned
is the quick and easy way to do it. Why aren’t they just teaching kids to do that?
So for example, we all learned to borrow when we subtracted,
but this doesn’t really show you what you’re doing. It doesn’t really show you what borrowing
is. And so one of the ways the Common Core tries
to explain this is with a number line because subtraction is really about finding the distance
between two numbers. You start with the number you’re subtracting
and you take little hops up to a more round number. So you go 10 between 90 and 100.
So you’ve sort of broken down the distance and you add these numbers together.
There’s another method called the counting up method, and this is also for subtraction.
Count up from 38 to 40. Then from 40 you want to go up to the next big round number, which
is 100. Then you need to go from 100 to 300. And then
from 300 to 325. So that’s the distance between 38 and 325
are these numbers that i’ve circled. You get this idea in your head that numbers
are flexible things made up of other numbers. 40 is a 38 and a 2
The standard algorithm is the easy and quick way to do it. Students absolutely still have
to learn to do it that way. But the idea is that this gives them a better
understanding of what they’re doing. And that there are a lot of ways to do this.
There isn’t just one right way to find the solution to a math problem.
You read through the standards and they seem like really reasonable, good ideas. The most
important thing is how they’re taught. Teachers understanding what’s expected of
them, having the resources to teach it well. Because otherwise you do end up with
math problems that don’t seem to make any sense at all.
And in some cases that’s just the parents not understanding it.
But it some cases it probably is a bad lesson plan, a bad textbook, a teacher who doesn't
quite understand what they’re supposed to do differently now.
There are definitely bumps in the road.