*Incredibles 2* Asks: What's the Right Way to Solve a Math Problem?

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Everyone knows I like to analyze the trailers of upcoming movies—in particular, movies that I’m excited about. In this case, it’s Incredibles 2. I have high hopes for this one since the first Incredibles was really great.

In the trailer, we see Mr. Incredible doing his job—helping out with math homework (that’s one of the things dads do). Here is how that goes down.

Dash: “That’s not the way you’re supposed to do it, dad. They want us to do it this way.”

Mr. Incredible: “I don’t know that way—why would they change math? Math is math. Math is math!”

This is what makes a great movie. There are probably quite a few parents that can relate to this. But who is right? Is math math? Or are you supposed to do it some other way? How about an example? Solve the following:

Timmy has 2,314 pieces of candy that he want to share between among his group of 8 friends. How many pieces of candy does each friend get?

Yes, I think that’s a silly question—but I also think that it’s pretty realistic (as an example of something you would see in a math class). To answer this question, you would need to divide the total number of candies by the number of friends. That means 2,314 divided by 8. The “math is math” way to do this is with long division. Yes, you remember long division. It looks something like this:

I’ll spare you the details of long division, but I’m sure that’s what Mr. Incredible is thinking about. He knows how to do long division because that’s the way they taught it in his day. Dash, on the other hand, wants to solve this problem with some other method. But which way is right? Honestly, some of these old math ways just don’t really do anything useful.

Let’s consider long division. Suppose you trained super hard such that you are a long division expert. What does that get you? Can you do some division problems? Yes. Can you do a quick division problem while shopping in the grocery store? Probably not—unless you have a nice sheet of scratch paper handy. Oh, I know what you are going to say. There are some other useful methods to divide numbers without paper. But in the end, these are essentially just tricks.

Long division is not the best way to divide in everyday life—it’s probably better to just use your smart phone. Then why is long division still covered in math courses? Does it lead to a better understanding of the concept of division? Does it lead to a more robust understanding of numbers? It’s possible it could—but not if it’s taught as a simple recipe to remember and repeat. This is probably why Mr. Incredible is frustrated. He wants the old way, but Dash is trying the new way.

Could you even make long division useful? Absolutely. Check out this example.

So this, is in essence the battle between “new math” and “math is math.” It’s a process of rethinking the way we teach ideas in math to hopefully bring about understanding. The problems come around when parents try to help their kids without really understanding the basics. Hopefully, when Dash grows up he will be able to help his super kids with math.

Oh wait … you thought I was going to do some type of Incredibles physics analysis. Sorry.