In this worksheet, round decimal numbers to the nearest whole numbers and then estimate the answer to an addition.
Example
Estimate the answer to the addition by first rounding both decimals to the nearest whole numbers.
10.3 + 26.9 

+ 

= 

Answer
10.3 is less than 10.5 so it rounds down to 10.
26.9 is more than 26.5 so it rounds up to 27 (remember that .5 numbers go up).
Then add 10 + 27 to get 37.
10.3 + 26.9 

+ 

= 
