## Key Concepts

- Doubles Fact
- Near Doubles Fact

## Introduction

### Doubles

To get a double of a number, we add the same number to itself.

For example, double of 3 is 3 + 3 = 6.

**Example 1: **

Jenny has 4 marbles and she has bought 4 more new marbles. How many marbles does Jenny have?

**Solution:**

The double of 4 is 8.

### Doubles fact

**Example 2:**

Find 5 + 5.

**Solution:**

Let’s take some cubes to solve this.

Doubles fact: 5 + 5 = 10

**Example 3:**

Find 9 + 9.

**Solution:**

Let’s take some cubes to solve this.

Doubles fact: 9 + 9 = 18

### Near doubles fact

When adding numbers that follow each other, use the knowledge of doubles to help add the numbers.

3 + 4 is same as 3 + 3 + 1 = 7

**Example 4:**

Find 4 + 5.

**Solution:**

Double fact: 4 + 4 = 8

4 + 5 is one more than 4 + 4.

Near Doubles fact: 4 + 5 = 9

**Example 5:**

Find 10 + 8.

**Solution:**

Double fact: 8 + 8 = 16

10 + 8 is two more than 8 + 8.

Near Doubles fact: 10+ 8 = 18

## Exercise

- Complete the doubles fact. Use cubes if needed.

8 + 8 = ______ - Choose all the pictures that represent a double.

- Complete the doubles fact. Use cubes if needed.

2 + 2 = ______ - Complete the doubles fact. Use cubes if needed.

5 + 5 = ______ - Complete the doubles fact. Use cubes if needed.

10 +10 = ______ - Use the doubles facts and solve the near doubles. Use cubes if

needed.

3 + 2 = ______ - Use the doubles facts and solve the near doubles. Use cubes if

needed.

5 + 6 = ______ - Use the doubles facts and solve the near doubles. Use cubes if

needed.

### Concept Map

### What have we learned

- Use Doubles fact and add two numbers that are the same.
- Use Near Doubles fact and add two numbers that follow each other.

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