Many teachers have developed "tried and true" lessons that they look forward to teaching-- mystery powders is one that these authors like. Originally part of the Elementary Science Study curricula in the 1960s, there are now many different versions of this well-known activity in which students examine physical and chemical properties of…

Children love snow days, even when they come during the warmest weather. In this lesson the snow isn't falling outside, it's in the classroom--thanks to "Snowflake Bentley" (Briggs Martin 1998) and several models of snowflakes. A lesson on snow demonstrates several principles of practice for using models in elementary science. Focusing on snow was…