An Oldie Revisited: The Border Problem



Tuesday, April 19th, 2016
Here's one of my favorite oldies. (No, not the photo—the border problem.) I was so pleased to see this math investigation included in Jo Boaler’s latest paper. This blog post presents a detailed lesson plan for using the border problem with students and also includes a five-minute video clip to give you a sense of how the instruction went with one class.

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Does Changing Subtraction to Addition Make It Easier?



Thursday, April 7th, 2016
Teachers have always told me that paper-and-pencil subtraction when problems call for regrouping is hard to teach and hard for students to learn. Much harder than addition. So why subtract when you can always add? That’s what my friend Nicholas thought, and he taught me how.


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A Reponse to Joe Schwartz’s Blog about Algorithms



Monday, April 4th, 2016
I was recently planning to teach my friend Ruth Cossey’s elementary math methods class at Mills College in Oakland, California. Digging through my collection of student work, I found a paper from a third grader I had interviewed. When doing interviews, I typically ask students to figure out answers in their heads, but I agreed when Nomar asked for paper and pencil for some of the problems.

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