## Thursday, January 14, 2016

### Day 83: Number talk, Transformations, Quadratic Regression model

My day started with me sleeping in and just stretching at the gym and taking a shower at 7:30. Then I went to Safeway and got my breakfast burrito, coffee, and a chicken parmesan for lunch.

On my way to work I got a text from our secretary Dianna to see if I wanted to sub Ms. Ko's 7th grade class. I gladly accepted. I printed out 4 copies of a number talk I saw on twitter. It was my first dot talk and definitely the students first. I had 3 different students participate. One of the students was the first and last to participate. I was happy with the results, especially, because one student saw 3 squares of 4, and subtracted 2 because two were double counted:

Today was a special estimation. It was me standing in front of the MLK Jr statue on the Sojourn trip this past year. Students estimate the height. A lot of students thought it was 3 1/2 to 7 times the height of me. Some converted to inches first, and some students rounded my height up.

I posted the photo on twitter and I think a lot of teachers may have used it:

In first period students did Becoming an Artist. They translated, rotated, and reflected figures to form a rocket ship. I demonstrated with patty paper how to rotate 180 degrees clockwise about a point.

 I like how this student understood the distributive property for converting my exact height, 5'11" to inches. I tried my best to demonstrate the way he explained it. You can see at the top how the previous student rounded my height up to 6 feet, then multiplied by 5.

Then students took an assessment on 3 skills: solving for y and fraction busters, system of equations w/ equal values, and transforming a triangle.

 I saw a student with one of these from the Everyday math curriculum set. I want to see how much a class set of these would cost.

In accelerated students worked on Dan Meyer's Desmos activity Penny Circle. A lot of students tried a linear model and realized it was wrong. A lot of students underestimated. They saw that the exponential model predicted an answer that was way too big. They agreed it was a quadratic model.

I asked students what were the actually finding out and why was it a quadratic? Eventually students suggested it with the area of a circle. I asked for that formula. They said area equals pi times radius squared. Then I asked what is a quadratic and what is the basic equation of it? Eventually they said x squared or y equals x squared. I asked them what they noticed about the two equations. They realized  both were raised to the 2nd power.

 Here you can see their models and I can go back and look at their responses.

Some students finished early and got to do the Desmos Regressions tour.

Then students took an assessment. Unfortunately, I wrote nickels instead of times in a coin word problem, so their system of equations did not solve correctly. I will have them retake that portion in the last section of class on Tuesday.
 Here is an overlay of the students different models. I wish I took a picture of their screen where it showed their data points going up in a curve.
After work I setup my board for Tuesday, saw some old students, made copies in the office, and then decided to go to American Bull and invited our dean of students. I randomly bumped into my old coworkers from the previous school I worked at and had some great conversations.

When I got home, I put away clothes, ironed, and did some chores, then relaxed and watched TV.

 And I got my desmos t-shirt and the stickers I ordered. They also threw in a personal note, pencils, and some Desmos sunglasses! Those will stay at school for sure.