Build a coin sorter from a cardboard box

How to do it

Measure the width of every US coin — penny, nickel, dime, quarter. Cut slots in a long cardboard ramp inside a shoe box: dime-width first, penny next, nickel after, quarter last (because slots only catch coins smaller than their width). Tip a handful of mixed coins down the ramp. Watch them sort themselves. Adjust the slot widths until it works clean.

What you'll need

• A shoe box and ruler

  Free

• Box cutter (you handle)

  Amazon