Math Monday: 12-Card Star Puzzle

Craft & Design Paper Crafts Science
Math Monday: 12-Card Star Puzzle

By George Hart for the Museum of Mathematics


Here is a challenging star construction you can make from twelve playing cards. The underlying geometric form is the third stellation of the rhombic dodecahedron. However, there is a twist in this design that makes it somewhat tricky (but fun) to assemble.


To make your own copy, cut four slits in each of twelve cards, as indicated by solid lines in the template below.


Fold each on the diagonal shown as a dotted line. Try assembling them by connecting long slits to short slits, guided by the image above.


No tape or glue is needed; it all locks together when the final piece is inserted. If you give up, you can find detailed instructions here.

8 thoughts on “Math Monday: 12-Card Star Puzzle

  1. nualan says:


  2. Goli Mohammadi says:

    So cool and simple! Totally gonna try this one. Thanks George!

  3. Brian Givens says:

    Made it! This was a timely post for my star-a-day project:

  4. lmm says:

    I not only made this one, but I made one using 30 pieces cut using the template for this one. The cards were a little heavy and I had to cheat to keep the weight of the star from pulling pieces apart as I got near the end. This is one of the few stars that I needed glue for.

Comments are closed.

Discuss this article with the rest of the community on our Discord server!

Gareth Branwyn is a freelance writer and the former Editorial Director of Maker Media. He is the author or editor of over a dozen books on technology, DIY, and geek culture. He is currently a contributor to Boing Boing, Wink Books, and Wink Fun. His free weekly-ish maker tips newsletter can be found at

View more articles by Gareth Branwyn
Maker Faire Bay Area 2023 - Mare Island, CA

Escape to an island of imagination + innovation as Maker Faire Bay Area returns for its 15th iteration!

Buy Tickets today! SAVE 15% and lock-in your preferred date(s).