For delivery in time for Christmas (in-stock items), order through 12/08 and choose Regular Shipping.
Give children real items that sink (rock, penny, bolt) or float (cloth, shell, pumice). This activity is so engrossing that it will be in constant use in your classroom. The depth and clear sides of the plastic tank allow a good view of items as they sink (or float).
Children will love experimenting with items such as clay, which can be molded to sink or float. Be prepared for children to suggest their own items to experiment with! Ages 3+. Items may vary from those shown.