Math Lesson

Grade Level: 1-3

Objectives:    Students will:

1. Learn the vocabulary and geometrical concepts of triangles, squares, diagonals, hexagons, rectangles, parallelograms, and trapezoids.
2. Sort and classify geometric shapes
3. Develop spatial reasoning abilities

Materials:

3" squares of construction paper (two colors)
scissors
glue or paste
9" x 12" newsprint for mounting

Activities/Procedures:

1. Give square and scissors to each student. Have them fold on diagonal, open up, and cut. Discuss vocabulary words: square, diagonal, triangles.
2. Reassemble triangles into square.
3. Make different shapes with two triangles
a. Two edges of the triangles must touch
b. The two touching edges must be the same length
4. Identify the two additional shapes: large triangle and parallelogram. Select two students to paste onto newsprint and display on board. Label with appropriate names.
5. All students pair up and take a different color square. Cut on diagonal as before.
6. Using the same rules, partners make shapes using the four triangles. Each shape is pasted onto newsprint and displayed.
7. In a group discussion, sort the shapes by row into the various categories: rectangles, squares, triangles, trapezoids, and hexagons.
8. Discuss properties of different shapes, introducing the above shapes that they might not have come up with in their exploration.
9. Discuss color combinations within the shapes.

Extensions:

1. Make as many different color combinations and shapes as possible, without repeating any of them.
2. Cut out the pasted shapes and sort according to shape and color.
3. Sort according to number of sides.
4. Discuss if flipping and rotating makes new shapes.
5. Discuss area of the various shapes.

Assessment:

Have students identify key characteristics of the various shapes they have created and explain why they grouped the way they did.

WA EALR’s:

Mathematics
1.3 Understand and apply concepts and procedures from geometric sense
2.1 Investigate situations
2.3 Construct solutions
3.1 Analyze information
4.3 Represent and share information

Adapted from "The Four-Triangle Problem", A Collection of Math Lessons by Burns and Tank, Math Solutions Publications, 1988.