Estimate Sum of Decimals

Estimate Decimal Sum with Rounding: Learn

How to Estimate a sum by rounding:

  • Round each term that will be added
  • Add the rounded numbers

Example: Estimate the sum of 0.988 + 0.53

  • Round 0.988 + 0.53 to be 1 + 0.5
  • Add the rounded numbers to obtain the estimated sum of 1.5
  • The actual sum of 0.988 + 0.53 is 1.518

Some uses of rounding:

  • Checking to see if you have enough money to buy what you want
  • Getting a rough idea of the correct answer to a problem

Estimating with Rounding: Practice

Estimate the sum by rounding the two numbers.


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