Why I Like Using Open Number Lines (Though I Don’t Like the Name)



Wednesday, February 25th, 2015
This post is about subtraction, which is typically difficult for students to learn and for teachers to teach. Think about 503 – 398, for example. To estimate the answer, I can change the problem to 500 – 400 (rounding 503 to 500 and 398 to 400). That gives me an estimate of 100, which I know is close. But how can I know if the actual answer to 503 – 398 is greater or less than 100? I raised this question with third graders.

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The Game of 2048



Thursday, February 12th, 2015
Several months ago I received an email message from my friend Sandra. She wrote, "If you want something new to distract you, try playing the new game 2048. I’m finding it addicting." I took Sandra’s advice and downloaded the free app. And, like Sandra, I found it addicting. But it also led me to think more about what I think is important when we teach math.


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Relearning High School Math



Tuesday, February 3rd, 2015
My 15-year-old granddaughter Charlotte is a diligent math student. When I checked recently to see how she was doing with her Algebra 2 math homework, I found her sitting on her bed with her computer, iPad, and phone, managing to text friends on and off as she worked. She asked me for help.

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