Illuminations

I often find myself at the NCTM Illuminations website on Sunday nights, trying to come up with an idea for Monday's lesson. They have a lot of good ideas for lessons and activities. I don't usually use the worksheets that come with them, but they're a good starting point and are pretty easy to adapt to fit my classroom.

Last night, I was looking for an activity to review slope-intercept form with my students. I found this. Students place ordered pairs on a graph as battleships. They draw numbers out of a hat to use as the slope and write equations of lines that will "sink" the battleships. NCTM's suggestion was to have students do the activity with a partner and then check each group's paper for accuracy at the end of class. I knew I wouldn't have that kind of time, so I changed it a whole class activity instead. I had each row of students choose a point to place their battleship. I put the numbers for the slope in a bowl and had random students choose one at a time. We worked as a class to figure out which battleship we could sink. They had a little bit of a hard time figuring out where to start on the y-axis, but got the hang of it after a few examples.