## Thursday, April 2, 2015

### Day 133: 8 cm Dilated...

Me: "We've been talking about transformations.  What are the three that we've discussed over the past week?"
S: "Translation, rotation and reflection."
Me: "Good. So I want to talk about a fourth transformation.  What comes to mind when you hear the word 'dilation'?"
S: "PREGNANCY!"

This was how I started my day.

Me: "...true... Anything else?"
S: "The pupils in your eyes."

And then we were able to talk about mirrors, lenses and the human brain for a whole period.  The kids were fascinated and asked great questions. (8th period didn't have this discussion because the side conversations and interruptions were out of control.)

In order to give them a better understanding of dilation on a coordinate plane, we did an activity that had them graph points, create several shapes and then dilate them from the origin.  We looked at what effect a dilation has on the coordinates of the shape.

I'm reminded again that my students really enjoy DOING rather than calculating.  This activity had them plotting points and connecting dots rather than finding measurements.  They had to think about what happens to the shapes, which is much more concrete.  When there are things to draw, the concepts makes much more sense.

I don't know why I keep forgetting this.  Note to self: DO MORE HANDS ON ASSIGNMENTS!  (You dolt!)

A discussion of radicals in geometry lead me into an explanation of fractions using rectangles just as I did in math 8 earlier in the year.  Several of the students shut down and put their heads down, either not caring about the underpinnings of the mathematics that they think they understand, or not wanting their mathematical worldview to be modified.  I understand both of these sentiments and sympathize.

But that's not going to stop me.

I teach what needs to be taught for my students to think like mathematicians, not for them to be calculators or formula recitation machines.

I'm ready for the long weekend.  Ready to spend some time with my family and friends.

Although, I may have to neglect all of them.