3.OA.D.8: Solve two‐step word problems using the four operations. Represent these problems using equations with a letter standing for the unknown quantity. Assess the reasonableness of answers using mental computation and estimation strategies including rounding.

Solve two‐step word problems using the four operations. Represent these problems using equations with a letter standing for the unknown quantity. Assess the reasonableness of answers using mental computation and estimation strategies including rounding.

Example Problems
Estimate by rounding to the nearest tens place:
Estimate by rounding to the nearest tens place:
Estimate by rounding to the nearest tens place:
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