Blocks are the best foundational math toy there is, says Bongiorno. They introduce the idea of balance and develop basic comparison and sorting skills relating to different shapes and colors. Painted blocks are also a good tool for building vocabulary. When playtime comes around for your baby or preschooler, sit down with her and name the colors and shapes as she grabs them. Then, help her group and stack them too. Playing with blocks cultivates a basic awareness of architecture, says Bongiorno, and teaches kids about how things fit together to form a structure.