When you estimate you round the numbers and then work it out in your head.
That way you quickly get an approximate result.
Example: 38 + 51
38 is almost 40, and 51 is almost 50.
So work out 40 + 50 = 90.
The right answer is close to 90.
Then choose the number that fits best.
The numbers filled in show the solution.
Example
- 90
- 50
For parents
What does this exercise practice?
Estimate results by rounding and judge them sensibly.
Common pitfalls
Children sometimes round in the wrong direction. Say it out loud: 38 is closer to 40 than to 30.
How to practice at home
While shopping, round the prices roughly and add them up in your head, then compare with the receipt.
Related: Calculation, Compare