I remember when I was a kid at school and the teacher first taught us how to round numbers. The technique he taught us is known as arithmetic rounding, also called round-half-up. In this case, values ...

Use place value cards to practice rounding numbers to the nearest ten and hundred. Warm up with a Mystery Math Mistake to hunt for the mistake made counting up on the number line. Use place value ...

Editor's Note: I just thought I should mention that there's an ongoing, ever-evolving, and dramatically different presentation of this topic entitled Rounding 101 on my personal website. We'll start ...

Scientific American presentsMath Dudeby Quick & Dirty Tips. Scientific American and Quick & Dirty Tips are both Macmillan companies. In the last Math Dude episode, we learned the ins and outs of ...