This one is easy fun and somehow a little bit magical. Makes a great little math gift. The challenge is to make rectangles with pieces #1-5, #1-6, #1-7, and #1-8 (as below)
Details, Instructions and Template Here.
Here are the “versions” in a short video.
These pieces are made in relation to eachother so there are many versions possible. Note that piece 1 can have extra added to the bottom.