Tuesday, March 9, 2010

A New Take on Slope

I haven't taught the basics of slope for a few years. Rather than use the tried and true method of drawing graphs on the board and finding their slopes I thought I'd take pictures around the school of lines and we would find the slope of those lines. It was a very small difference but the images seemed to capture the attention of many of my students. Many of them commented on where the picture was taken (Are those the stairs at the North end of the school?), some were even curious when I took the pictures.

After a quick demo of slope using Geogebra I started with just an image an asked how we could find the slope of a slanted microphone. Someone quickly pointed out that we needed a grid. We overlaid the picture with a grid and counted the squares for the rise and the run. On the next image we introduced a coordinate system and the formula for slope so that we didn't have to count the squares. The end result was something like this.

I wanted students to find the slope of the roof for this church. Somebody asked if they had to do both sides. We discussed how they thought the results from both sides would be related. They were then asked to confirm their guesses.

Overall most students were tuned in. I think there were a few that thought I was babbling and wanted me to get to the traditional lesson. It make take a few lessons like this for them to realize that this is the lesson.

1 comment:

  1. You're doing a great job Dave. Fantastic idea to use photographs. Great ideas start with a spark, that needs to be fanned into a flame, that other can warm up too. (c) 2010 Daniel Beylerian