Today's problem was one that I was reminded of at a recent professional development session (thanks @chrisleechss ).

This question generated a lot of discussion. Is 1 a big slope? Does it matter if it's negative or positive? There were lots of good conversations as students continued to solidify their understanding of slopes. For groups that finished early I asked how their answers would differ if they were allowed to use the numbers 0-9.

The consolidation of this problem led us to talk about horizontal and vertical lines. We talked (again) about the slopes of these lines but we also talked (unexpectedly) about the equations of horizontal and vertical lines.

The main lesson for today was investigating parallel and perpendicular lines. I gave this investigation. It was good for students to practice graphing lines but I think I need to rework it for them to get more out of the perpendicular lines portion.

We'll consolidate the investigation tomorrow.

## No comments:

## Post a Comment