Text-weight paper in colors and patterns of your choosing (look for two-sided paper)
1/8" hole punch
Thumb tacks or push pins
Pencil erasers (detached from the pencils)
8" lengths of wooden dowel
Hot glue gun
Making the Pinwheels:
Cut paper into 5 1/4" squares. Fold each square in half diagonally, then fold the resulting triangle in half laterally. Unfold. You'll now have four triangles marked by the creases in the paper. Use your hole punch to pierce a hole in one outer corner of each triangle (choose the same corner for each).
Using the fold lines as a guide, cut toward the center of the square from each of the four corners, stopping when you are 1/2" from the center of the square. Punch a 1/8" hole in the center of the square.
Bring the four hole-punched corners together at the center of the square; match them up over the hole at the center, and press a tack or pin through them and into a pencil eraser at the back of the pinwheel.
To create the stems, attach a segment of dowel to the eraser at the back of each pinwheel using hot glue.