## Wednesday, September 9, 2015

### Day 7: Newton's Revenge Day 1 & Polygraph: Parabolas

Most students were way off on the estimation today. Almost all students underestimated. We highlighted students who used yesterday's fact that there were 28 almonds in a 1/4 cup. Then some estimated how many cups would fit in the big container. It ended up being a staggering 40 1/4 cups. (1/4 of a cup was a serving)

Students had 5 minutes to discuss the Newton's revenge situation before we had a whole class discussion to understand what we needed to find out and how we would. I went over the stations for measuring height and reach. There were a total of 7 stations so all groups could stay busy.

After measuring their height and reach, they put their initials on a sticky dot and plotted it on the class graph. Also, instead of writing down a class list I made a Google form where they submitted their info to. I had students submit on my computer and to save time made a Google URL shortener so students could use their own phone to submit to the form. It makes it SUPER easy to paste it into the Desmos link that CPM provides in the lesson. So we will analyze their scatterplot and the one digitally tomorrow.

In accelerated, I didn't take any pictures or video. We met in the computer lab where we started with estimation. Then I had them play Polygraph: Parabolas. Students once again experienced the frustration of not knowing the vocabulary necessary to accurately describe parabolas.

I did point out some students who asked "Does it open up or open down?" Also another student asked "Does it go through all four quadrants?"

So, halfway through class I wanted to focus our attention on a question: How can we describe a parabola? So we took y=x^2 -1 (y equals x squared minus 1)

I asked them how we graphed equations before we knew y=mx+b. They said plug in points. And how do we organize it? A table. They found values for -2 to 2 and graphed it.

So, we could describe the parabola if it opens up or opens down. Also, they noticed there was an x-intercept at (1,0) and someone else piped in yeah and at (-1,0). They also said there was a y-intercept at (0,-1). They also said the parabola looks symmetric, like a mirror. So I asked where is the mirror. They said the y-axis. I asked what is the equation of the y-axis. One student knew and remembered it was x=0 (Alex D.).

Davin also remembered the vocabulary vertex. It's hard to describe, so I asked the students, is there a highest or lowest point on a graph? The lowest point in this case is where the vertex is, at (0,-1). I asked them what would the graph look like if the vertex was the highest point? They responded that it would be opening down.

Tomorrow each table group will get a quadratic function and have to graph it and describe it using all the vocabulary we went over and to put all their work on a poster.

When they got back to the game, someone said, "What are roots?" I said that was vocab I hadn't gone over but it's a synonym for x-intercepts. Great session.

#### 1 comment:

1. I really liked how you used the Polygraph activity before discussing key vocabulary - gave students a reason to learn the new words!