Here's an idea that lots of librarians already do and that I know at least one person has posted for Flannel Friday before (sorry, can't remember who!). I've heard it called "Roll-a-Rhyme" most frequently. Basically, you make a big die (singular of dice!) and roll it. Whatever comes up, is the nursery rhyme that you sing/say.You can build a box out of cardboard. I actually bought mine from Discount School Supply. I'm pretty sure I didn't pay $36, and I don't think I got number cards with them, but it was a few years ago. I made the nursery rhyme cards in Publisher. The dice have vinyl pockets so you can change the contents really easily.