Grade 4 · Math · Lesson 14

Check Answers with Inverse Operations

Every operation has an opposite called its inverse. Addition and subtraction are inverses of each other. Multiplication and division are inverses of each other. You can use the inverse operation to check whether your answer is correct — this is one of the most powerful self-checking strategies in mathematics.

What this lesson teaches

1Identify the inverse operation for addition, subtraction, multiplication, and division
2Use the inverse operation to check whether a calculated answer is correct
3Detect and correct calculation errors using inverse checking
4Apply inverse operations as a self-checking strategy in multi-step problems

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