Want to know what interleaving feels like? Try these quick math problems!

It's been awhile since we've talked about interleaving!

Years of cognitive science research have established that interleaving – simply rearranging the order of retrieval opportunities – can increase (and even double) student learning.

But what does interleaving actually look like? This week, try it for yourself!

Here's What Interleaving Looks Like


Research by Doug Rohrer and colleagues demonstrates that the simple approach of interleaving and mixing up concepts to be learned can result in a large benefit for student learning – whether it's songs, math, science, vocabulary words, art history, and even baseball.

For example, when students complete four addition, four subtraction, and four division problems (e.g., AAAA BBBB CCCC), they can go through them without thinking about which strategy is appropriate. They don’t even have to read the words.

But when the math problems are interleaved (ACB BAC CAB), students have to choose and retrieve the appropriate strategy for each problem. Same exact problems – just simply rearranged! A critical key to interleaving: mix similar concepts to promote students' discrimination (like a fruit salad!).

Try these math problems and submit your answers on our Google Form:

  • A bug flies 48 miles east and then 20 miles south. How far is the bug from where it started?

  • A bug flies 48 miles east and then 14 miles north. How far is the bug from where it started?

  • A bug flies 48 miles east and then 6 miles west. How far is the bug from where it started?

These word problems appear to be similar and you may have applied the Pythagorean Theorem. But did you notice that the last problem requires a different strategy to solve it correctly (answers here)? Welcome to interleaving!

Sometimes concepts look alike, but they can require different strategies. And we want our students to recognize up from down, addition from subtraction. Note that this is a very simple example of interleaving. Of course, you'd want to mix up similar concepts (Pythagorean Theorem with other geometry concepts) to encourage students to discriminate. Click here for more examples of math problems by Doug Rohrer and colleagues.

If problems are mixed up and interleaved, students need to choose a strategy, not just use a strategy without thinking. It's not about tricking students; interleaving is a low-stakes desirable difficulty to improve understanding.

Take the content you already have, interleave it, and boost learning!