Sand is an excellent tool for exposing children to a wide range of sensory experiences.
Kids can be creative as they can squish it, shape it, and mold it in Different containers. At the same time be social as while they are playing in the sand they will talk about what they are doing.
You can hide marbles or other objects to make them think how to find and counting the number of marbles in the sand.
It never dries out so it can be used over and over. I store mine in ziplock bags.
You can also add food coloring to have different color Moon sand.