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We can estimate the answer to an addition sum by rounding the numbers to the nearest hundred before we add.

 

Example 1

Estimate the answer to the following sum by rounding the numbers to the nearest hundred and then adding.

 

326 + 567

 

Answer

326 + 567

  ↓        ↓

300 + 600 = 900

 

Example 2

Estimate the answer to the following sum by rounding the numbers to the nearest hundred and then adding.

 

150 + 415

 

Answer

150 + 415

  ↓        ↓

200 + 400 = 600

 

Remember that 150 rounds up to 200, 350 rounds up to 400, 250 rounds up to 300 etc.

10 questions