My pet peeve is math lessons that have third, fourth, and fifth graders "discover" pi. The idea is that they will measure the diameter and circumference and notice the pattern. In my experience students in that age group don't measure accurately enough.
I started teaching pi in reverse. I tell my students what the ratio is up front and then we see if we can measure a set of circles accurately enough in millimeters to reach that ratio.
Of course, they have this idea that they should have dessert pies for that day, so I created this worksheet that plays on the homophones.
