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2nd grade math - addition & subtraction word problems with unknowns

Clip 1/11: Pre-Lesson


In her pre-lesson reflection, Mia Buljan anticipates challenging her students to be more explicit about their strategies to break larger numbers apart into tens and ones. She anticipates students’ misconceptions, hoping to uncover them through talk and sharing. She understands that her students are revising their thinking and are able to explain how their thinking changed, that their “conversations are more mature, now that they’re 7!”

Teacher Commentary

By this time in the year, I see a wider range of strategies students use to get “unstuck” when they are working on a problem, negotiating the use of their tools, and applying them to the task at hand. I want them to be looking for more efficient ways to count. Earlier in the year, we started working on this, and now we’re making a shift to new kinds of thinking, requiring a reaffirmation of how students can “attend to precision” in their communication, establishing and reinforcing shared criteria for a good mathematical argument: “The more precise we can be, the more mathematical it is.” My students use whiteboards as a tool to support their proofs.