3.4 – Linear Equations and the Intercept Form

Day 1:

As the students entered the room, I had them write on their notes what I had on the board:

• Recursive Rule
• Explicit (Intercept) Form
• Table
• Graph

I then had them copy down a simple table from the board which was really the first few lines of the sports car’s distance from Flint from the previous section.

Time in minutes	Miles from Flint
0	35.0
1	35.8
2	36.6
3	37.4

And we changed the data into the other three forms. I spent a lot of time explaining that given any of the four forms, students should be able to change it to any of the others.

I made sure that students saw the relationships between the four forms, such as the starting value is the y-intercept, or that the table is increasing by the same amount that appears in the rules. We talked about slope a little because kids brought it up.

The second problem that I gave them was with a graph (of y = -2x + 5) that needed to be converted to the other three forms. Then I gave them the 3.4 Notes, which involved more of the same, but I wanted them to be as successful as possible with the “boring” stuff before we add stories to the list of things we should be converting situations into. So I’m planning on doing the investigation on day 2, then assigning the homework (#1, 3, 4, 5, 6, 7)

For the first day, I gave them the worksheet from the Extra Practice materials on 3.4 to do.

3.4 Notes

Day 2:

I gave a warmup that took quite a long time, but I think that it was beneficial. Helping kids move from the explicit formula straight to the table was difficult for them. Once they began, they did pretty well, although there are still numerous issues with scales on graphs when the data jumps from 2000 to 5000. I spent the rest of the day going over the previous day’s homework in preparation for the quiz, which is below.

The amount of money that Gladys makes each week selling furniture is

y = 200 + 0.10x

where y is the amount of earnings and x is the amount of furniture sold.

• Make a table using values of x = 0, 500, 1000, 1500, 2000, and 5000.
• Write a recursive formula
• Make a graph

3.4 Warmup

3.4 Quiz