# Section A: Practice Problems Odd and Even

## Section Summary

Details

In this section, we learned that groups of objects have either an even or odd number of members. We learned that an even number of objects can be split into 2 equal groups or into groups of 2 with no objects left over. We learned that an odd number of objects always has one object left over when you make 2 equal groups or groups of 2. We also learned that even numbers can be represented as an equation with 2 equal addends.

Odd

Even

## Problem 1 (Pre-Unit)

How many dots do you see?

1.

2.

3.

## Problem 2 (Pre-Unit)

Select 3 correct equations.

## Problem 3 (Pre-Unit)

Here are some pattern blocks.

How many corners are there all together on the pattern blocks? Explain or show your reasoning.

## Problem 4 (Lesson 1)

1. Noah and Lin have 13 crayons. Can they share all of the crayons equally with no leftovers? Explain or show your reasoning.

2. Noah and Lin have 16 colored pencils. Can they share all of the colored pencils equally with no leftovers? Explain or show your reasoning.

## Problem 5 (Lesson 2)

Mai is planning a dance and wants everyone to dance in pairs. For each number of students, decide whether everyone can dance in pairs with no one left out. Explain or show your reasoning.

1. 14

2. 17

3. 18

## Problem 6 (Lesson 3)

For each image, decide whether the number of dots is even or odd. Explain or show your reasoning.

## Problem 7 (Lesson 4)

Can each number be written as a sum of two equal addends? Explain or show your reasoning.

1. 12

2. 15

3. 18

## Problem 8 (Lesson 4)

Decide if each expression represents an even number or an odd number. Explain or show your reasoning.

## Problem 9 (Exploration)

This classical design is called the “flower of life.”

It is made of shapes that look like this:

1. Is the number of these shapes in the design even or odd? Explain or show your reasoning.

2. How many of the shapes are there in the design? Explain or show your reasoning.

## Problem 10 (Exploration)

What are some things in the classroom that you know there are an even number of without counting them? Explain your reasoning.