I came across this tip today and wished that I had this when I was teaching art. I thought it was so simple and useful for teachers, that I decided to add a post to my teacher blog!
If I had a quarter for every time a student needed to draw a circle and we looked all over for a lid that is just the right size! I know...some of you may say, use a compass! But if you teach art, you may know that the compass is never around when you need it. And these days, a compass with a point is a no no. The old fashioned compasses that we used when I was in school, are now considered dangerous. But this technique eliminates the need for a compass.
Hope this helps in the classroom!
How to Draw a Perfect Circle
by DaveHax on Youtube