Baffling Decimals

19 Apr

As I am catching up on reading Steven Strogatz‘ brilliant articles on math, this one in particular is really making me want to teach elementary school math again! I dream of being Deborah Ball and creating sassy lil kids who debate why odd numbers are odd. I also dream of being Jaime Escalante and randomly yelling “GANAS!” to kids while they’re taking integrals…

Anyways, have you heard the Verizon billing debate? I want to share this with everyone I know, so that they can share in some of the pains of teaching math.

For example, this week, we started talking about the Quadratic Formula, therefore, we had to discuss square roots. I listed the square roots in order going down.

When we established that these were in ascending order and that the square root of 1 was 1 and the square root of 4 was 2, we got to approximating what the square root of 2 was.

After testing 1.4 and 1.5 and figuring out that it was a number in between, I asked the class to choose a number between 1.4 and 1.5.


“O… k… What if I add this?,” I say as I write ‘$’ in front of each number, “and this?,” as I add a zero at the ends.

“OH!” “1.45!” “1.47!” “1.42!”…

So then we get to seeing that square root of two is between 1.41 and 1.42, which then bodes the next question, “What number is between 1.41 and 1.42?”

**silence** x2

And then someone yells, “There no such thing!”

Ah yes, my future Verizon workers…

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