Unit Plan 25 (Grade K Math): Analyze & Compare Shapes

Focus: Compare two-dimensional (2D) and three-dimensional (3D) shapes by attributes; describe similarities/differences and parts (e.g., sides, vertices/corners, edges, faces, flat/curved surfaces).

Grade Level: K

Subject Area: Mathematics (Geometry—Shape Attributes)

Total Unit Duration: 5 sessions (one week), 30–40 minutes per session

I. Introduction

Students build a shared language for how shapes are alike and different. They handle real objects and math manipulatives, sort by attributes, and explain thinking using complete sentences. By week’s end, they can compare 2D vs. 3D, name parts, and justify a sort with at least one similarity and one difference.

Essential Questions

• How can I use shape words to tell how two shapes are alike and different?
• What parts of shapes (e.g., sides, corners, faces) help me compare?
• How do roll/slide/stack tests help me describe flat and curved surfaces?

II. Objectives and Standards

Learning Objectives — Students will be able to:

1. Distinguish 2D (flat) vs. 3D (solid) shapes and name common examples.
2. Use attribute words (e.g., sides, vertices/corners, edges, faces, flat/curved) to describe shapes.
3. Compare pairs of shapes using at least one similarity and one difference.
4. Sort shapes into categories and explain the rule for the sort.

Standards Alignment — CCSS Kindergarten (threaded across the unit)

• K.G.4: Analyze and compare two- and three-dimensional shapes in different sizes and orientations, describing their similarities, differences, parts (e.g., number of sides and vertices/“corners”) and other attributes (e.g., having sides of equal length).
• Mathematical Practices: MP.6 (precision of vocabulary), MP.3 (explain and critique), MP.5 (use tools/manipulatives), MP.7 (look for structure in attributes).

Success Criteria — Student Language

• I can tell if a shape is 2D or 3D and say why.
• I can name parts like sides, corners, faces, and edges.
• I can say one way the shapes are alike and one way they are different.
• I can sort shapes and explain my sorting rule.