Subtraction as the Inverse of Addition with Child 5
This second grader uses a known number combination (3 + 9) to solve a subtraction problem, showing an understanding of how addition and subtraction are related as inverse operations.
Focus on the Child videos are taken from one-on-one interviews with individual children. The interviews are designed to elicit evidence of children’s mathematical thinking. They are not teaching episodes or formal assessments.
Why is this important?
Fluent computation requires reasoning about the numbers and the situation. Here, a second grader solves a change unknown problem efficiently by applying a known fact to a new situation.
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The Early Math Collaborative works to improve math instruction for young children in three ways:
- Professional development
- Research
- Dissemination