Kids love to sit in the sand and play with dump trucks. They can create roads, load the truck, drive it across the sand and dump it out again. They can learn to work as a team to get the sand moved to a new location or sift the sand through slotted pans and pretend they're panning for gold. They also can get the sand wet and build sandcastles.
Preschoolers can use sand to study the effect of erosion when water runs over sandy surfaces. Fill up a small pan with sand and have your child pour the water from various heights to see the effect running water has on our beaches and rivers. She can also practice measuring by pouring sand into various containers and comparing the amounts in each. You can use measuring spoons to help your preschooler understand the basics of fractions.
A sandbox seems like a wonderful place for a child to let off steam and develop his creativity, but some sand that is used in sandboxes is made from unsafe products. It often will contain crushed rock and might contain carcinogens. Check the label carefully and research a company's website before purchasing a bag of sand. River and beach sand are often safer alternatives.
The temptation to throw sand comes easily to small children, but sand that gets in the eyes can be painful and difficult to remove. If it happens, gently flush the area with water. If the sand is stubborn, a trip to the doctor might be needed.
Preschoolers should always be supervised when playing in a sand box. Some will try to eat the sand, and even if it is otherwise safe, ingesting it can be a problematic practice for a child.
An outdoor sand box should always be covered with a lid. A platform-like cover can be built for larger, handmade sandpits. Tarps or canvas covers also work. Small plastic sandboxes often come with a fitted lid. If the sandbox isn't covered, neighbor cats might use the sand area as a litter box, and bird droppings also can be a problem. Children can catch pin worms from infected sand.