Using Notecards to Connect Area Formulas and Deepen Understanding

This is a session for 5-7 grade mathematics teachers or instructional coaches. During the presentation, each participant will be given a notecard and use scissors to construct new 2D-shapes using that notecard. Participants will use the area of the notecard to connect areas of the shapes. This interaction will help them (and their students) conceptually make sense of area formulas for a triangle, parallelogram, and square, starting with the area formula for a rectangle. Through this activity and discourse around this activity, participants will be encouraged to collaborate and build on formulas explored earlier in the session to find possible formulas for the area of a trapezoid. This activity aligns with Mathematical Practice 7 (Look for and make use of repeated structure) and Grades 5-7 Geometry standards because students engage in visualization and spatial reasoning as they interactively compose and decompose shapes, and develop connections between area formulas