In this activity, we will be learning how to round decimal numbers. 

 

Numbers with 2 decimal places have 2 digits after the decimal point.

To round one of these numbers to the nearest 1 decimal place number think of a number line.

 

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 7.50 round UP.

 

 

Here 7.35 is between 7.3 and 7.4, but rounds up to 7.4 to one decimal place.

 

Let's try some example questions. 

 

Example 1

Round 12.63 to one decimal place.

 

Answer 

12.63 is between 12.6 and 12.7, but is closer to 12.6.

12.63 rounds down to 12.6.

 

 

Example 2

Round 10.38 to one decimal place.

 

Answer

10.38 is between 10.3 and 10.4, but is closer to 10.4.

10.38 rounds up to 10.4.

 

Example 3

Round 16.65 to one decimal place.

 

Answer

16.65 is halfway between 16.6 and 16.7 and so we round up.

16.65 rounds up to 16.7.

 

Now it's your turn to try some questions like this.