Today I took the suggestion from Mr. Webb and Ms. Whitt and divided Sublette's Cutoff and Who Will Make It between the groups in my classes. In other words some groups did Sublette's Cutoff and some did Who Will Make It. The 2 activities were similar enough that I was able to introduce the activities pretty easily. They are asked to plot data for 3 different families and then draw 3 different lines of best fit. Then they are asked to answer questions and make estimations with the lines. I think that even I have a better understanding of why we do lines of best fit after teaching these last few activities. I know that I "knew" what it is for but I do not think that I have applied it within a context very many times. Over the course of this week my students will have used lines of best fit within at least 3 or 4 different contexts. The discussions about what the x and y intercepts were so meaningful and productive! We are really talking about slope and the y-intercepts without formally introducing the equation. It is so cool to see how the authors develop each of the concepts. I think it is hard to appreciate until you teach an entire unit.
Today after we finished graphing and "sharing out" the answers I asked the students to share with me the meaning for the x-intercept and the y-intercept. I had one student say, "The y-intercept is the starting point and the x-intercept is the ending point," and the BELL RUNG!!! UGH! I was very excited that she said that and I wanted to discuss it with the class...there is always tomorrow.
In 5th period today I did something different. I wrote the assignment on the board and referred the students to the assignment as they walked in the door. All I did was tell them to read over and it and put the "entry" into their notebooks. Dude! They got on it! I had one student figure out the answer to #1 (which deals with multiple constraints) by the time I had answered roll! AMAZING! As a whole they worked harder today than I have ever seen them work. Once the one student got the answer he walked around and helped other groups. I would ask them to explain how they got their answer and wouldn't give them candy (the great motivator) unless their explanations made sense. They don't need me! Well...not as much as I think they do. HAHA!