Children have played in sand for thousands of years, building the same skills today as they did centuries ago. While it may look like your child is just having fun in her sandbox, she's actually bolstering several areas of development, from fine motor coordination to imaginative play and social skills. Mixing a small amount of water completely changes the consistency of the sand, allowing even more opportunities for creative exploration and development.
Fine Motor Development
Fine motor development is the coordination of dozens of tiny muscles in your child's hand and wrist. These are the same muscles eventually needed to write letters and fasten buttons. Coordination and strength develop with age and improve with practice. Digging, shaping and raking through damp sand with a small tool builds these small muscles and requires your child to practice coordinating them. The weight of wet sand adds extra resistance, further developing these important muscles.
Gross Motor Development
Gross motor development is the strength and coordination of larger muscles throughout the torso, legs and arms. When your child fills a bucket with sand, stands up and carries it to the alternate side of the sandbox, she's promoting muscle strength and coordination in her shoulders, torso, back and forearms. Turning from side to side to gather or pour sand strengthens her core muscles. Pushing sand with her feet or dragging her heel through the sand to make a canal supports gross motor development throughout her entire leg.
Manipulating dry and wet sand encourages cognitive development by giving your child a chance to anticipate and experiment with different conditions and tools. Sifting sand through a colander or pouring it over a dry water wheel demonstrates how changing a single factor, like the colander size or how fast she pours sand, can change the end result. Poking a stick through a mound of wet sand or drawing a picture on the outside of a damp sand castle reveals how differently sand reacts when it's wet.
Because most sandboxes are relatively small, your child will be forced to work amicably, if not cooperatively, with other children. At a beach there's enough sand for everyone, but sharing a sandbox with friends or siblings encourages practice at cooperatively building sand castles, sharing tools or taking turns serving "food" made from wet sand in the shape of a pizza. While the close quarters can lead to disagreements, they can also serve as motivation for conflict resolution.