Lesson 7

The purpose of this lesson is for students to identify shapes as flat (two-dimensional) or solid (three-dimensional) as they build and sort shapes.

In previous lessons, students explored, identified, created, and counted two-dimensional shapes such as circles and squares. In this lesson, students are not expected to use precise vocabulary so they may use words like “lying flat” to describe a two-dimensional shape and words like “solid,” “taking up space,” “tall,” or “sticks up” to describe a three-dimensional shape. Throughout this unit, students will hear and use “flat” and “solid” to describe two-dimensional and three-dimensional shapes. The names of common three-dimensional shapes will be introduced in a future lesson.

• Each student needs a piece of clay.
• Gather a cone and cylinder to display.

• Each group of 2 needs a set of solid shapes and a set of cards.

• Gather materials from: 
  • Counting Collections, Stage 1
  • Match Mine, Stage 1
  • Shake and Spill, Stages 1-4

The standards ask students to “identify shapes as two-dimensional (lying in a plane, ‘flat’) or three-dimensional (‘solid’).” How does building shapes out of clay help students distinguish between two-dimensional and three-dimensional shapes?