How do you estimate the sum of 202 and 57?
1 Answer
One number is about 200, the other is about 60.
The sum will be about 260.
Explanation:
For an estimate you think the word "about".
If you are travelling, you would say, "It will take about 2 and a half hours to get there" (Not 2 hours 24 mins and 30 seconds!)
There were about. 50 people at the party.
In this case we are adding two numbers. One is about 200, the other is about 60.
The sum will be about 260.
The amount of rounding depends on the size of the numbers and how accurate you need to be. It would be reasonable to estimate the number of people at a meeting to the nearest 10, but that would not be reasonable for the number of people at a soccer match or music festival.
You might be asked to estimate by rounding to 1 significant figure, or to the nearest whole number, or to an appropriate level of accuracy.
Estimation is a useful skill and it helps if you estimate the answer to a calculation first.
If your real answer is very different, you will know something is wrong,
