Key words for rounding and estimating

Here are some words that you'll come across when rounding and estimating.

For example with the sum:
197 – 50 = 147

Rounding
To write a number to a given amount of accuracy.
      Rounding 197 to the nearest 100 would be 200.

Estimate
To give a rough answer that may be a little less or a little more than the actual result.
      To estimate 197 – 50 you may instead work out 200 – 50 to give an estimate of 150.

Approximate
An answer that is not exactly correct but is close enough to be useful in working out a sum.
      To approximate 197 – 50 you may instead work out 200 – 50 to give an estimate of 150.

To the nearest.. rounding off..
A guide to how accurate your rounding needs to be.
      Rounding 197 to the nearest 100 would be 200.
      Rounding off 147 to the nearest 10 would be 150.

Actual
The correct answer to a sum.
      The estimate of 197 – 50 is 150. The actual answer is 147.

You'll find more maths words explained in the Skillswise Glossary.