Lesson Plan Source

The lesson will begin with the students seated at their desks. The students will be shown a picture of a butterfly. The students will be asked what it means to say that the butterfly is symmetrical. Students may recognize that one side of the butterfly is the same as the other. Students will be told what symmetry means and told that many things in nature often have symmetry/are symmetrical. They will then be shown several examples (a leaf, a rainbow, a daisy,etc.  They will then be asked if they can name anything in the classroom that has symmetry.  Examples will be given. The students will then be introduced to the activity. Each student will receive a copy of dot paper. Once distributed, the class will be shown how to fold the paper in half lengthwise along the center line. With the paper folded in half, I will use an overhead projector to demonstrate how to cut out a triangle, leaving the uncut fold as one side. Students will be asked to do the same. Before children unfold their papers, the students will be asked if someone can draw a picture on the chalkboard of how he or she thinks the figure will look once the paper is unfolded. The children will then be asked to unfold their papers to see what figure was created. Students will be asked to tell how the halves on both sides of the fold are alike. Some students may recognize that both halves show triangles that have exactly the same shape and the same size. The students will then be told that when the halves on both sides of a line match in shape and size, we can say that figure is symmetrical and we can call that line a line of symmetry. The students will then be given a picture of a heart cutout. Students will be asked to draw a line of symmetry on the heart. Students should recognize where the line of symmetry is. Students will then be given construction paper in order to make other shapes-a square, a circle, or an invented one. How to fold and cut the paper will be demonstrated. For each shape,  students will be asked to draw the line of symmetry on it.