Judith L. Bellonio
Purpose: Develop an understanding of fractions using tangrams.
Materials: Overhead projector
Overhead tangram pieces
Tangram sets (various colors) - each student needs one set
Teacher directed activity. Lesson may work best with students working cooperatively in groups of two so that they may combine their different-colored tangram sets for ease in naming pieces.
Activity: Below is a tangram set. Students are to give each of the seven pieces a fractional name (1/2, ¼, etc). Teacher may want to start by asking students the fractional names of the two larger triangles asking how many large triangles it will take to cover the completed tangram set. Then move on to the medium-sized triangle by having student first determine how many medium-sized triangles it takes to cover one of the larger triangles. Next move on to the small-sized triangles as they compare to the medium-sized triangle. Once the medium and the small-sized triangles' fractional names have been established move on to the small square and the parallelogram.
(figure available in print form)
Pre-Lesson Activity: Using colored construction paper, have students create their own person tangram set. Refer to http://www.askdrmath.com/trscavo/tangrams/construct.html for a lesson plan.
Internet Activity: www.enchantedmind.com. Click on Puzzles and then tangrams.
Students will use their mouse to arrange tangram pieces into various shapes.