Primitive Old Painted Wooden Clock Face with Moveable Arms

I assume this clock face would have been made for teaching time, but it seems curious that each hour would be divided into five rather than six segments, marking 12 minutes at a time rather than 10! Whoever made it did take care to make those delineations, though, carving them into the wood as well, it appears, as marking them with graphite. I was just immediately attracted to the look of it, with the red painted numbers popping against the much aged white, and what looks like a number "1" at bottom left. The pointing hands, tightly secured with a bolt on the backside, still turn just fine, with some of the red paint still holding on to the minute hand. Found in Pennsylvania and quite an old thing I believe. 

11 3/8” x 9 1/4” x 11/16”, old and crusty but structurally sound, with just a little warping to the wood.