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Common Core math, explained in 3 minutes

Libby Nelson
Libby Nelson is Vox’s policy editor, leading coverage of how government action and inaction shape American life. Libby has more than a decade of policy journalism experience, including at Inside Higher Ed and Politico. She joined Vox in 2014.

Nothing goes viral like a bad Common Core math problem, something that takes a simple subtraction question and turns it into a multi-step process that confuses anyone over the age of 20.

But there's a reason the new math is complicated. One goal of Common Core is developing number sense: an understanding of how numbers can be broken down into units of smaller numbers. You might do this at the convenience store. If you're paying cash for something that costs $4.27, you could pay $5.02 to make sure you get all your change in quarters.

But learning math like a recipe, a series of steps you have to go through to get a result, doesn't always do that.

math gif

(Joss Fong)

Just like dollars can be broken down into quarters, dimes, and nickels, ordinary numbers can be broken down into units of hundreds, tens, and ones. The new method of teaching math tries to help students understand how numbers are put together. But kids still have to learn the standard algorithm — the basic, familiar, and usually fastest way to solve math problems.