Lesson plan

# 4. Understand that 2D and 3D shapes are identified as flat and solid (C)

teaches Common Core State Standards CCSS.Math.Content.K.G.B.4 http://corestandards.org/Math/Content/K/G/B/4
teaches Common Core State Standards CCSS.Math.Practice.MP7 http://corestandards.org/Math/Practice/MP7

## You have saved this lesson plan!

Here's where you can access your saved items.

Dismiss

Lesson objective: Understand that 2D and 3D shapes are identified as flat and solid.

Students bring prior knowledge of 2D shapes from Grade K, Unit 8, K.MD.A.2. This prior knowledge is extended to identifying and describing 3D shapes as students sort 2D and 3D shapes based on if they're flat or solid. A conceptual challenge students may encounter is all 2D shapes are solid because they compose 3D shapes.

The concept is developed through work with real-life 3D objects, which will help students understand how to determine if a shape is flat or solid.

This work helps students deepen their understanding of equivalence because you can compare two shapes to determine if they are the same or different.

Students engage in Mathematical Practice 7: Look for and make use of structure. Mathematically proficient students are able to look closely and use structure to identify, describe, and create shapes.

Key vocabulary:

• attributes
• flat
• solid

Special materials needed:

• 2D shapes (pattern blocks, attribute blocks etc)
• 3D shapes