Many websites have recipes for play dough- I have tried a few and like this one best. In my opinion, it has the same consistency as the real thing. The same recipe is on several websites - I have no idea where it came from originally. Aside from the obvious crafty fun and educational benefits, rolling and cutting play dough is good practice for rolling and cutting cookie dough. Once your child masters even rolling in play dough you can move on to the real stuff. :-)
