## Saturday, August 21, 2010

I mentioned in the previous post that one of my goals is to encourage my kids to parse instructions and to translate them into mechanical procedures or a diagram. Here is a good (fun) example from Neufeld Math, which Ms. Cookie had linked to; I think I'll use it when I introduce compass constructions. The idea is that I'll let the group struggle with it for 10 or so minutes and not help them out much. (I'll force them to go back to the written directions.) Then, we'll go over the correct results; I'll let a kid present the solution if they are able to parse all the instructions correctly.

In the space provided, draw a circle and then carry out these steps:

• IMPORTANT: Keep the same radius used to draw the original circle, for this entire exercise.

• Select a point on the circle’s circumference. Label it A.

• Center your compass on A. Use the compass to draw an arc that passes through the center of the original circle and intersects the circumference in two places. Label those points B and C.

• Use the new intersection point C as your center to draw a second arc that passes through the edges and the center of the original circle.

• Continue around the original circle in clockwise to construct more arcs that pass through the original circle's center and its edges, in order to complete the pattern and to return to point C.

• Erase all the marks outside of the original circle, leaving only the arcs that are inside. At this point, you should have what looks like a flower with 6 petals inside a circle.