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DecimalsGeneral InterestMultiplicationNumber and OperationsNumerical ReasoningReal-World ProblemsVideosWord Problems

When You Multiply by 10, Just Add a Zero? Horrors!?!

Have you ever asked students to solve 12.6 x 10, and they respond that the answer is 12.60? I have, many times. Students who do this apply a pattern that works when they multiply whole numbers by 10—they tack on a zero to the end of the number they’re multiplying. But then they apply the same pattern when working with decimals. What can we do?
Marilyn Burns
October 1, 2018
General InterestProblem SolvingVideos

The 1–10 Card Investigation

The 1-10 Card Investigation has a big payoff with students. It engages their interest, involves them with making sense of a problem and persevering to solve it, and gives them experience with evaluating their progress and changing course as necessary. Plus it has a playful aspect that too often is lost in math class.
Marilyn Burns
June 29, 2015