These are called the red rods. This is great for the children to decipher between sizes, as well as problem solving. Always hold the ends and carry them with great care. As the children are carrying these, they quickly realize when they get to the larger ones, how difficult it is to hold the ends. It really helps them decipher that it's much larger than it's much larger when they can?t' reach the end. I'm going to start with the largest rod. Now I have put all the red rods in order by size. Now I'm going to put them away. Always put them away, opposite to the way you took them out. So you will put the largest one away first. That is the red rods.