Use the Radius Ruler in the 4th or 5th grades to teach a student at a younger age that there is a way to measure that ball they are playing with, or that curve they just drew. It is FREE online at radiusruler.com and on facebook for teachers and students. They can copy, paste, print and build their own Radius Ruler. When students learn the concept of Radii at a younger age it will give them the confidence to go further in math and science. There is a video on facebook, "How to Build Your Own Radius Ruler."
Idea No. 69