Our set, Number Rods - (Extension Cards), consists of 25 cards divided into four sections and with a visual control for errors on the back of each card. In this post, you can explore all four sections to see how the set is designed in a sequential scaffolded manner, to maximize children's independence in their learning. For presentational purposes, we used the Table Top version of the Number Rods. You may use the standard Number Rods as well.