I got this idea from a wonderful author, named Jeff Johnson. The title of the book is Everyday Early Learning: Easy and Fun Activities and Toys Made from Stuff You can Find Around the House. If you would like to visit his website go to www.explorationsearlylearning.com I altered it a little from his book. I just used numbers 1-10 from the card deck, punched a hole in each corner of the card and connected it with a metal ring (I used clear packing tape to tape the ring tightly closed). Quick, easy and cheap to make.