In this activity, we will be learning how to round decimal numbers with two decimal places to the nearest whole number.
Numbers with 2 decimal places have 2 digits after the decimal point.
To round one of these numbers to the nearest whole number, we can simply ignore the number in the second decimal place!!
We look at the number in the first decimal place, that is in the tenths place.
Numbers ending in 1, 2, 3, 4 round DOWN.
Numbers above this, those ending in 5, 6, 7, 8 and 9 round UP.
Remember that halfway numbers, such as 7.5 round UP
Example 1
Round 12.63 to the nearest whole number.
Answer
12.63 is between 12 and 13 but it is nearer to 13.
Ignore the 3 and look at the 6 in the tenths place.
6 rounds the number up to 13.
12.63 rounds up to 13
Example 2
Round 10.38 to the nearest whole number.
Answer
10.38 is between 10 and 11 but it is nearer to 10.
Ignore the 8 and look at the 3 in the tenths place.
3 makes the number round down.
10.38 rounds down to 10.
Example 3
Round 16.57 to the nearest whole number.
Answer
16.57 is halfway between 16 and 17 but it is nearer to 17.
The 5 in the tenths place makes it round up.
16.57 rounds up to 17
Now it's your turn to try some questions like this.
