Today we were trying to "get back into the swing of things" in algebra. The All Four, One activity asks students to consider the 4 representations of a linear function (situations, graphs, tables, and rules) and create a report on how to convert between one to the other. In the instructions the text gives a "common form" for writing a linear equation as f(x) = ax + b where a is the rate of change and b is the starting point. This description fits nicely with the way graphing has been introduced and developed over the past few weeks. I "borrowed" a worksheet from another IMP teacher that already had the scenarios written out (i.e. From situations to graph, from graphs to rules, etc...). I gave my students 35 minutes to work on the task. I had to help them do a couple before they were able to work in their groups.
I am trying to improve my students' presentation skills. Therefore today I told them that I was going to "roll the dice" to randomly call on at least one person in each group. That is nothing new. However, I made each student come to the document camera and show his/her answer instead of allowing them to talk from their desks. Then I talked them through correcting the answer if it didn't fully explain how to do the conversion. I told my classes that we were going to work on giving better presentations. I tried to move toward the back of the room so that students would at least appear to be addressing the class (Jim Delawder tip!). I did have a couple of students in my 3rd Block class laugh at other students. It worked out well because their groups hadn't gone yet and the boys who were laughing had to present instead of the random "roll of the dice." I hope this helps to get them to quit teasing each other during presentations.
The main thing I liked about this assignment was that students talked over and over about the importance of finding the starting point (which was always on the y-axis) and the rate of change. Today was another day that I loved that I had all kinds of graphs on chart paper hanging around the room to refer to.
I did not spend much time on Straight-Line Reflections. However, I did use Desmos on my Ipad and project the graph for #3. It is really cool how you can just pinch or expand the graph in Desmos so that it is easier to identify the y-intercept and the rate of change. As of right now we find rate of change by discussing the change in the graph over 1 x value. I am going to assign #4 from Straight-Line Reflections as a warm-up tomorrow.
My 5th period completed the If I Could See This Thing activity. It is interesting to see how many students could figure out the correct population (after the 90% decrease) but their explanations on paper were "train wrecks." Writing mathematical expressions correctly is a topic that is difficult for that class. I was excited because some students found the 90% and then subtracted from the original population and some found 10% of the original. It is cool when students come up with the different ways to complete the same task.