This thing says it was copyrighted in 1968 but it sure looks older than that. I guess it has aged, just like the rest of us. This wheel is 5.5 inches across and in stained shape. But it's perfectly usable. The Penny Saver side (it has a penny on it!) helps the homemaker determine, for example, how much per ounce she's paying when she spends 50 cents for 4 pounds of lard. If she needs to buy 10 pounds of lard but only knows the price for the 4 pounds, then this wheel helps her figure that out, too. What a lifesaver!
On the other side we have the Cook-Aid, with an oh-so-charming little drawing of an old-fashioned cast iron stove. On this side of the wheel, one can learn how to double a recipe or change the proportions to something else. You can see that this specimen has been stained with something. It looks like grease to me.
All in all, this is a great little wheel for those of us who don't do math.