Next-generation HIGH-CONTRAST nesting blocks. Let your imagination run wild, stack and play all day, explore numbers and counting, and see where your creativity takes you! Our blocks stack 36 inches talland are designed to help kids learn their numbers 1 through 10, and associate those numbers with values based on the graduated block sizes. Why Black and White? Before a baby learns to reach and grab with their hands or crawl and sit-up, their eyes are providing important information and stimulation for their development. A baby's brain undergoes an amazing period of development from birth to three producing more than a million neural connections each second. High-contrast imagery offers the best opportunity for newborns to focus on visual stimuli and promotes visual exploration and engagement.