I was just sent a link to this site; all it is, is a handy one-page printable conversion chart for various US measures, metric measures, and US vs. metric measures. Includes even a comparative Fahrenheit vs. Celsius thermometer.
I got inspired by the blogpost Art School | Geometric Design with Islamic Art where Deborah shows how to make a neat flower design with seven circles, using a compass, and then coloring it using 2, 3, or 4 colors (or however many of your own). I think it ties in neatly with mathematics, and lets students practice drawing circles with a compass.
My girls loved the art/math project. Here are pictures they made:
Here are step-by-step instructions for the flower design:
1. Draw a line and a circle so that the circle's center point is on the line. Then mark the points where this circle intersects the line.
2. Use those points as center points, and draw two more circles. The radius is the same all the time, so make sure you don't change it on your compass!We used 5 cm as the radius, and that made the whole design fit neatly on a regular letter size paper.
3. Now note the two points marked in the picture. They will be used as center points in the next step.