# 3rd Grade - Check Precise Calculations Using Context

 Grade Level: 3rd Skill: Reasoning Topic: Check Precise Calculations Using Context Goal: Make precise calculations and check the validity, of the results from the context of the problem. Skill Description: Mathematical Reasoning: precise calculations, check validity or accuracy, problem solving The ability to calculate answers (add, subtract, multiply or divide without making mistakes) with precision and to check those answers to make sure they make sense.

### Sample Problems

 (1) What does precise mean? (To add, subtract, multiply or divide without making mistakes; to get an exact answer) (2) How do you check that 81 divided by 9 is actually 9? (9 x 9 = 81) (3) How do you check that 200 – 150 is 50? (50 + 150 = 200) (4) Does it make sense? Jane bought 6 bags of 10 crackers for her study group. Does she have enough for all 5 people to have eight? (Yes, all four people could have twelve) (5) Does it make sense? Mickey wanted to give Minnie a present for her birthday. He bought her a box of chocolates that cost \$20. He paid with a fifty-dollar bill and got a ten and a twenty back. Is that right? (Yes. He got \$30 change from \$50)

### Online Resources

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