The children loved working with the Math U See games. They were a great supplement to all the other activities we use.
Their favorite game was Skyscrapers where you use the rods to form the four corners and cardboard for the floors. Each of the corners has to add up to the same number.
Unfortunately the rods that come with the Math U See program are too small and unstable for most K-1 children. We had 1″ rods from another company that worked much better for this activity.
I would recommend buying this program as a collective group of homeschoolers and sharing the games and materials.