## Thursday, December 3, 2015

### Day 63 Reflection: Blog posts on y=mx+b and Finishing Exponential Decay

The estimation was a small curved vase. Surprisingly a lot of students thought the vase was bigger than the soda can. Then again many students thought it was  a bit smaller.

In 2nd through 5th period I reviewed the Learning Goal for the day and the Success Criteria specific to this day. It is as follows:

The instructions for the blog assignment are below today's post. Students created their own blog and wrote a new post. I asked them to copy and paste the questions from the learning log in the book to guide them in demonstrating their knowledge of y=mx+b.

Hw tonight 4-59 to 4-63 is a great practice. http://homework.cpm.org/cpm-homework/homework/category/CC/textbook/CC3/chapter/Ch4/lesson/4.1.6

In 2nd period Riley saw that when you insert a photo you can click insert from web cam. After you press allow in the window and when the popup appears below the URL part of the screen you can take a picture of your work. I encouraged students to make up a rule with different m and b values to help with their explanations.

To see student work, search for @joycemathletes on Twitter.

Students: not all of you finished or were expected to finish in one class period. I will be checking first drafts next Friday and would like you to comment on someone else's blog post from your class. If that person already has feedback, please give feedback to another person. This project can be finished at school and at home.

Remember students, if you did not share your link, no one can find it, so be sure to click send a tweet in the right hand column and if I don't see it remind me to tweet it out, thanks.

In accelerated we had to finish up exponential decay. Students predicted the rebound height if the ball kept bouncing 6 times from a drop height of 200 cm. They then conducted the experiment and got results that were from 5 cm to 20 cm off from their predictions. There were errors that they said could have been difficulty finding the rebound height, not holding the 2 meter sticks straight, and so on.

Students, such as Arthur, made the connection that the graph kept getting smaller and by a smaller amount each time. This was a great observation. They also saw that they were repeatedly multiplying the rebound ratio each time which lead them to see why an exponent was used. They then generalized it as a formula.

I asked them for the differences between that graph and the rebound versus drop height graph. They then compared it to the months versus bunny problem to see the similiarities and differences between exponential growth and exponential decay. Hans noticed that in the exponential decay a fraction was being repeatedly multiplied while growth a whole number is repeatedly multiplied.