round off

This is the term for reducing the number of digits in a number so that calculations are easier.

This means that although the result isn’t accurate, it’s close enough to the correct answer.

The two most common ways of rounding off are:

(1) Rounding up – this happens if the first digit we need to omit is 5, 6, 7, 8, or 9.

For example, 1189 rounded off to the nearest hundred is 1200.

(2) Rounding down – this happens if the first digit we need to omit is 0, 1, 2, 3 or 4.

For example, 1243 rounded off to the nearest hundred is 1200.

We can round off:

• to the nearest ten, for example, 8764 to the nearest ten is 8760

• to the nearest thousand, for example, 12 690 to the nearest thousand is 13 000

• to the nearest metre, for example, 12.8 m to the nearest metre is 13 m

• to a specific number of decimal places, for example, 34.867 to 1 decimal place is 34.9, and 0.0165 to 2 decimal places is 0.017.