STRAND: Number
TOPIC:
Decimal numbers
Rounding decimal numbers
to 2 decimal places
To round a decimal number correct to 2 decimal places, follow these steps:
1. Consider the digit in the third decimal place (that is, the thousandth’s place).
2. If it is less than 5, simply omit this digit and all digits that follow. (That is, omit all digits beginning from the third decimal
place.)
3. If it is 5 or greater than 5, add 1 to the preceding digit (that is, the one in the hundredth’s place) and omit all digits beginning
from the third decimal place.
WORKED Example
Round each of the following numbers correct to 2 decimal places.
a 0.239
b 4.5842
THINK
WRITE
a The digit in the third decimal place is 9, which is greater than 5. So add 1 to
the preceding digit (that is, to 3) and omit 9.
a 0.239 ≈ 0.24
b The digit in the third decimal place is 4. Since it is less than 5, simply omit all
digits beginning from the third decimal place (that is, omit 4 and 2).
b 4.5842 ≈ 4.58
Note that the sign ≈ is read as ‘is approximately equal to’.
Try these
Round each of the following numbers correct to 2 decimal places.
1 0.322
2 0.257
3 1.723
4 2.555
6 12.195
7 8.4678
8 25.033 78
9 18.333 333
5 4.308
10 0.166 666 6
 John Wiley & Sons Australia, Ltd 2001