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Monthly Archives

February 2015

General InterestNumber and OperationsNumerical ReasoningSubtraction

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

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.
Marilyn Burns
February 25, 2015
General InterestTechnology

The Game of 2048

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.
Marilyn Burns
February 12, 2015
General Interest

Relearning High School Math

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.
Marilyn Burns
February 3, 2015