## Friday, November 20, 2015

### Day 56: Baby News, y=mx+b, Systems

I thought about making an estimation problem based on the baby being 1.39 cm at 7 weeks, and a typical baby is between 40 and 50 centimeters at birth (36 weeks). I quickly realized this relationship is not proportional or linear so I will just show the picture. They were quite happy for me.

The estimation was how many ounces are in a glass? Students quickly said it was a champagne class, and a lot of them offered that they'd seen them with orange juice for mimosas. Surprised how much they knew. Most students estimated less than the can and I liked their reasoning.

I had students start on 4.1.4 with a participation quiz and reviewed up to writing an equation from looking at a line. This is student's first formal introduction to the equation y=mx+b. First students listed the equations from yesterday and were prompted to write down all their observations of their similarities. The best answer I saw all day was y=___x + ___. They remembered that format from the CPM Silent Board game. Some students used words like slope and y-intercept for m and b respectively. I prompted students what does m and b tell you about the pattern? Students thought m was the number of tiles added each time, or the growth. B was the number of tiles in Figure 0 or where the pattern starts.

 The positive and negative behaviors, cooperation, quotations. Participation Quiz.

The last problem we reviewed was a graph where Figure 0 had 1 tile and it grew by 3. Students said it was y=3x+1. I frequently reminded many students today when they wrote 4x+1, and 4x+3, those were expressions not equations. Then they put y equals. It sounds small, but it is very important.

In every class I did community building with mathography before taking an assessment on Skills 9 and 10. Trimester 1 final is on Tuesday and Trimester 2 will start with skills 10,11,12.

 Harrison presented his system and elimination work here. They earned 4 cents per capped bottle and lost 2 cents per broken cap. They had earned a total of 6 cents. The second equation is there were 15 total bottles worked on. You can see he multipled the second equation by 2 and then added the first equation to it to eliminate the y variable. He also wrote his answer properly as a point of intersection coordinate pair.

 I thought this poster's equation was advanced, I just wish they explained how they saw this rule. Some students asked their high school siblings to help them with the rule. I was delighted to hear their curiosity.

In accelerated students solved a system of equations word problem that they solved using elimination and substitution. Then they practiced equal values, substitution, and elimination method by choosing the most efficient strategy.

After school many students retook skills after doing corrections, explaining errors, and showing me evidence of homework.

I put up a larger majority of the CC8 4.1.1 tile pattern posters and made some great observations from them:

 I marvel at the rule here. They clearly saw it a certain way, I wonder if knowing what Figure 100 looked like helped them.

 Hard to read but 4 - (x+1)^2 + 2(x+1) +1 is quite a large equation!

 A couple gaps but that is 16 posters of high quality work up there. Going to fill another wall.