Playing card constructions

By George Hart for the Museum of Mathematics

At The Math Museum, we think it’s important to challenge oneself with mind-expanding tasks. Here are two rather challenging constructions which look simple, but may stymie you for hours. When you’re done, you’ll have something unique to show your friends. The ball at left is made of thirty cards; the one on the right uses sixty. Two decks of cards, a pencil, and a pair of scissors are all that’s necessary. Because of the tricky interlocking pattern, they hold together without tape or glue. If you want to polish your maker skills, try slicing up two decks of cards using these templates, then just slide them together.


Detailed directions and mathematical background are available here. Francesco de Comite has taken this idea and gone wild with it, rendering many other possible patterns here. Most have not yet been built, so you can be the first to make them! [Editor’s note: If you do, post them to the MAKE Flickr pool and post the link below!]


Math Monday: Mathematically-correct breakfast