Activity 1:
Models of 2-dimensional geometric shapes (circle, square, triangle, rectangle, and rhombus)

Activity 2:
Clean a one-pound coffee can and tape an old sock to the top of the can.

Activity 1: Describing Shapes (recommended for a small group of about 6-8 students)

Give each student a model of a geometric shape: circle, square, triangle, rectangle, and rhombus. Shapes should be in different sizes (e.g., large and small). Direct a student to choose a specific shape (e.g., a triangle). Ask the rest of the students to find the other triangles and hold them. Students close their eyes to share and describe attributes of the triangle. Ask, "What do you feel?" Continue with the additional shapes, eliciting information about attributes.

Activity 2: Mystery Shapes

Prepare a mystery can. Clean a one-pound coffee can and tape an old sock to the top of the can (cut out the toe area of the sock). Students will be able to reach their hand inside the sock and down to the shape but still not be able to see the shape inside the can.

Place one of the geometric shapes from Activity 1 in the "mystery can" and give the can to a student. Students take turns reaching inside the can to determine (by feeling) what shape is inside the can.

After each student names the shape (and before student takes the shape out of the can), always ask, "How do you know?" Expect students to describe the shape that they are feeling. Prompting questions to ask if students are having difficulty in identifying a shape follow:

• Do you feel any sides?
• Does the shape feel round?
• How many sides do you feel?
• Are the sides the same length?
• Does the shape have more than 3 sides?

When a student justifies the shape's name, ask other students to discuss whether they are in agreement with the name of the shape.