The Dot Game is one of the most advanced Casa math materials and is a first abstraction in the decimal system. The child must be very familiar with the hierarchy of the decimal system in order to process various mathematical operations. In particular, carrying over becomes visual and manual, which solidifies the child’s understanding of addition and gives a sense of ability in working with large numbers. The making of tens focuses the child’s attention on the process of carrying. The child learns that there are never combinations that come to more than 9, so it is just as easy to add tens of thousands together as it is units. What impressive work!