Create your own centimeter ruler. Then, estimate and measure with lengths with it. Warm up with a Mystery Math Mistake as you add two 2-digit numbers using a decomposition strategy. Think through ...

Quick: How many people did you see on the way home from work the other day? Was it more or less than the day before? Regardless of your answer, it’s likely you can’t explain what led you to it. Number ...

It's easy to not think about how little expenses add up over the course of an entire year. Use this simple mental calculation to quickly estimate the yearly expense and think about what better use ...

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