Rounding to whole numbers and tens

In many calculations you will be expected to round off your answer to the nearest whole number or to the nearest ten.

Example

Write 38.7 to the nearest whole number

Number line showing 38, 38.5 and 39.  38.7 is marked with a bead.

38.7 lies between 38 and 39.

38.7 is nearer to 39 than 38

So, 38.7 = 39 (to the nearest whole number)

Now try the example questions.

Question

Write 6.5 to the nearest whole number

6.5 lies between 6 and 7.

Number line from 6 to 7, showing 6.5 as mid-way.

6.5 lies mid-way between 6 and 7.

When this happens always round up

So, 6.5 = 7 (to the nearest whole number)

Question

Round 103.4 to the nearest ten.

103.4 lies between 100 and 110

Number line from 100 to 110, showing 105 as midway.  A bead marks 103.4.

103.4 is nearer to 100 than 110

So, 103.4 = 100 (to the nearest ten).