SCIENCE 21 is a K-6 integrated science sequence, developed at Putnam/Northern Westchester BOCES, in which experiences build science conceptual development from unit to unit and grade to grade. There are four units at each grade level with materials kits to conduct all the activities. The first unit usually deals with science processes and investigative tools. The other units provide relevant, grade-appropriate experiences in physical, earth, and life science. While some science programs permit random selection of unrelated units, the implementation of the SCIENCE 21 curriculum insures an integrated, deliberate sequence of instruction that addresses NYS Standards without gaps or overlaps.