• Display a group of flat shapes and a group of solid shapes that students created.
• “What is different about the shapes that we made first and the rest of the shapes that we made?” (The shapes that we made first are flat. The other shapes stick up.)
• “The first shapes that we made were flat shapes, such as circles and rectangles. Then we built some other shapes. What can we call these shapes?” (solid shapes, big shapes)
• “These shapes are solid shapes.”
• “Use your clay to make a flat shape.”
• “Use your clay to make a solid shape.”

The purpose of this activity is for students to identify shapes as flat and solid as they identify common properties and characteristics to sort shapes into groups. This sorting task gives students opportunities to analyze the structure of the shapes closely and make connections (MP7). If the sorting mat provided in the student book is too small for students to sort the shapes, consider giving students two pieces of construction paper, or ask students to put the solid shapes on one side of the table and the flat shapes on the other side.

• Invite previously selected students to share the way they sorted the shapes into flat shapes and solid shapes.
• “This group has flat shapes. This group has solid shapes.”
• Display a square.
• “Should this shape go with the flat shapes or the solid shapes? Why?” (It is a flat shape. If we put it on our desk, it doesn’t stick up.)
• Display a cube.
• “Should this shape go with the flat shapes or the solid shapes? Why?” (It is a solid shape. It sticks up and takes up space.)

The purpose of this activity is for students to choose from activities that offer practice with number and shape concepts.

Students choose any previously introduced stage from these centers:

• Counting Collections
• Match Mine
• Shake and Spill

Students will choose from these centers throughout the section. Keep materials from these centers organized to use each day.

• Display 4 pattern blocks arranged as pictured.

• “What would you tell your partner about where to put the red trapezoid pattern block?” (It’s under the yellow hexagon and over the blue rhombus.)