Wednesday, February 18, 2015

Fraction Number Talk

Today our third grade team went to a special training on teaching fractions for the new SBAC test. It was a pretty fun training, and it was really good to stretch our own thinking about fractions.

My favorite activity was a number talk we did on how to spot fractions. The presenter showed a picture like the one below and first asked us, "Who can spot 1/2?" 

The first couple answers were obvious, but as we pushed further we saw more and more halves. (Hint: change your definition of a whole to see more halves)

Then, she asked about one fourth. We were ready to show our thinking and came up with lots of answers.

Finally, she asked us about four thirds. This one was tough. The key here was that you had to think about a whole in a different way. Can you spot four thirds?

Well, there are many different possibilities, but the one I saw was the blue trapezoid plus the blue triangle. So, the blue trapezoid would be one whole and the triangle would be one third the size of the whole, making it four thirds.

Notice how many math terms I had to share to explain my thinking! That is so good for our kids!

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