This is a great activity for students learning about classification. You will need to make a simple classification kit of leaves having several varying attributes. You may choose to have 4 different shapes of leaves, 3 different colors, and with/without stems. So in this scenario, there would be a total of 24 leaves. You can simply make these out of construction paper using a stencil or template that you create. Laminate them for continued use. On the board create a large Venn diagram using 2 large circles, overlapping slightly. You will also need to make 2 sets of word cards for each attribute. Place each set in a pouch above a circle. Students can rotate through these cards when they use the bulletin board in order to sort for different attributes. You will need to place Velcro stripping on the board (some in each circle, some in the "both" area, and some outside of the circles in the "none" area), as well as on the backs of the leaves. Then your students can sort the leaves over and over again in different ways. They will have so much fun and they will learn about classifying.