How to round 9921 in to the nearest ten

Simple! My teacher taught me when you're rounding if the number beside the number (to the right) your rounding to is four or less let it rest five or more raise the score. you're roundingto the nearest 10 so you would be looking at the ones place. in the ones place there's only a one which is four or less so 9921 rounded to the nearest 10 is 9920.

9921

^ This is the tens place

Look at the number after that, if it's 5 or more than round up, if it's 4 or less, round down.

The number is 1, so we round down to 9920.