Much of the learning in preschool is embedded in play. I usually hide letters or numbers in the sensory bin for the children to find and match with a poster that is usually set along side it. This way, as a child finds a letter, the parents or teacher can explain what letter it is and what sound it makes. This type of learning is very natural and is easily absorbed by the child. The sensory bin also helps calm an anxious child as playing with the materials is soothing to him/her. I have found, as a preschool teacher that the sensory bin or reading to a child helps comfort the child in transitional periods such as separating from parents, starting something new, or the child is shy. So you can see why sensory bins are such an important element of our program. So much learning and reinforcement of concepts can be accomplished through sensory bins.