## Contents

Connections to the 3 Curriculum Threads

Featured Standards for Mathematical Practice

## Connections to the 3 Curriculum Threads

Learn more about the 3 Curriculum Threads

**Operations: **This unit involves counting (sides, vertices, corners, and individual shapes in a group), which deepens students’ understanding of addition.

**Number: **Identifying the number of objects in each group.

**Equivalence: **Can use equivalence with shapes by comparing 2 shapes (a triangle always has 3 sides; 2 triangles may look different, but they’re still triangles).

## Content Standards Addressed

### K.MD.B: Classify objects and count the number of objects in each category.

**K.MD.B.3: **Classify objects into given categories; count the numbers of objects in each category and sort the categories by count.

**K.NBT.A.1: **Compose and decompose numbers from 11 to 19 into ten ones and some further ones, e.g., by using objects or drawings, and record each composition or decomposition by a drawing or equation (e.g., 18 = 10 + 8); understand that these numbers are composed of ten ones and one, two, three, four, five, six, seven, eight, or nine ones.

### K.G.A: Identify and describe shapes.

**K.G.A.3: **Identify shapes as two-dimensional (lying in a plane, ""flat"") or three- dimensional (""solid"").

## Featured Standards for Mathematical Practice

**S.MP.3. Construct viable arguments and critique the reasoning of others.** Present their own arguments and respond to the arguments of others.

**S.MP.7. Look for and make use of structure.** Students look for similarities and differences.

## Major Representations Used

2D and 3D shapes

Real-life representations of 3D shapes

## Common Misconceptions

- Students may believe that because 3D shapes have 2D faces, they should be classified as a 2D shape. For example, a student may identify a cube as a square, because its faces are squares.
- Students may believe 3D shapes are also flat because they’re presented in a 2D format (on a piece of paper). 3D shapes need to be represented as tangible objects.