Math > Year 3

Estimation
Estimation means a sensible guess. It is done to find a value that is close enough to the actual answer, usually by using rounding.

For estimation, we use near numbers and mental calculations to check if the answers are close to being correct.

Near numbers
Near numbers are the rounded numbers that are closest to the actual numbers in a calculation.
The closer the near numbers are, the closer the estimated answer is to the actual answer.

While selecting near numbers, a balance needs to be maintained between two things.

Example 1: 34 + 71
To estimate the answer to the given calculation, we can find the nearest 10s to the given numbers.

Near number can be 30 and 70.
Estimated answer for the given calculation is 30 + 70 = 100

Example 2: 185 + 319

To estimate the answer to the given calculation, we can find the nearest 100s to the given numbers.

Near numbers can be 200 and 300 respectively.
200 + 300 = 500

The estimated answer for the calculation 185 + 319 is 500.

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