I apologize for the lack of pictures on this post. I'm in the middle of moving, and I can't find the cord to my camera.
With kids, broken crayons are inevitable. Instead of throwing out the odds and ends you collect, melt them down for shaped crayons for your kids.
You can use candy molds, ice cube trays, or mini muffin pans. I find the mini muffin pans to be easiest. Simply fill each mini muffin spot with the crayon pieces for each color. Put it in the oven until they melt, remove and allow to cool. You can also melt colors individually on the stove or microwave and pour into candy molds or ice cube trays.
Cheap, easy, and recycling otherwise useless crayon pieces.