Tuesday, March 1, 2016

Day 111: # Talks, Scientific Notation & Features of Quadratic Graphs

Before my math classes even started I had to substitute our drama teacher's class the second day in a row. I started class of with a dot talk that went pretty well. They finished their work early so I got to do a number talk for 18 * 5. We got some awesome ideas shared that I photographed below:

Abraham divided 18 by 2, to get 9, then multiplied 9 by 5 twice to get 45 and 45 to get 90.
Ethel shared the standard algorithm, as she called it the "classic way of solving it, visually carrying the 4 and adding it to the 5. Above that you can see Nina's awesome halving and doubling strategy. She took half of 18 to get 9, and doubled 5 to get 10, to make it 9 times 10.
Jennifer split up 18 into 10 and 8, multiplied each by 5, then added 50 and 40 together to get 90.
Gavin overcompensated. He knew 20 times 5 was 100, so he subtracted 2 times 5 from 100 to get 90. I demonstrated that students were using the distributive property mentally.
Here are some of the visual ways students saw the dots in the dot talk.
Alyssa saw 18 times 5 as 18 added repeatedly 5 times. She said she did 18 plus 18 to get 36. Then another 2 18's is another 36. 36 and 36 is 72 she said, and added 18 to get 90. I related that she was basically breaking up the 18 times 5 into 18 times (2 + 2 + 1).
In 2nd through 5th periods we started with estimation. A lot of students underestimated the number of pages in the Dr. Seuss book. The best reasoning I heard all day was the Dr Seuss book was 15 times smaller than the math textbook, so take 896, divide it by 15, and round up to 60. This was closest to the correct answer too.

We reviewed the commutative property of multiplication to simply multiplying power numbers. We once again reviewed what Carlene stated yesterday about if a number doesn't have an exponent, then it has a 1 as its exponent.

Then students worked on practicing moving the decimal when multiplying by powers of 10. They also worked on the FAL pre assessment, though after it for 5 minutes independently, then 4 minutes in group to verify, and finally we reviewed the answers. Tomorrow we will discuss the rank of smallest to largest, then the multiplying of two numbers as a decimal by a scale factor.
What we reviewed as a class before starting on the rest of the section.
In accelerated we reviewed a homework problem on whiteboards after practicing entering the class quietly. They described how to factor the quadratic to find the roots or x-intercepts. Then they simplified 2 expressions. Some students recognized it as the quadratic formula. I like how in CPM they review how to simplify a big expression that looks like it, before being introduced to the actual formula, which will happen in Chapter 9. Students realized that factoring and using the zero property got you the same answer as using the 2 expressions that got you the same answers.

Reviewing factoring, and then simplifying a complicated expression using the quadratic expression.
We reviewed what each of the 3 forms of a quadratic function look like and what clues they give you after they had time to remind themselves on their own.

Tomorrow students will construct a poster after developing success criteria after I introduce learning goals. Then they will match equations to graphs, and fill in missing equations. I want them to justify their matches on their posters. Then they will do a gallery walk where we work on giving constructive peer feedback.

No comments:

Post a Comment