Use rounded values to estimate close the answer to a calculation. This is a useful non-calculator skill. Refresh your knowledge with these guides on rounding and significant figures. Rounding to ...

When you do not need to speak or write about exact quantities or measures, learning to round numbers to 10, 100 or 1,000 can be useful. It can make calculations easier and it also helps when you are ...

For statistical and mathematical purposes, OpenOffice.org's Calc spreadsheet includes a variety of ways to round off numbers. If you're a programmer, you may also be familiar with some of these ...

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 ...