# Multiplying and dividing by 10, 100, 1000

## Multiplying and dividing by 10, 100, 1000 Revision

**Multiplying and dividing by 10, 100, 1000**

When we multiple by 10, 100 or 1000 we move the decimal place to the right. When we divide by 10, 100 or 1000 we move the decimal place to the left.

Make sure you are happy with the following topics before continuing.

**Skill 1: Multiplying by 10, 100, 1000**

When multiplying by 10, 100, 1000 move the decimal place to the right, the same number of places as zeros in the number.

Multiplying by 10 – decimal place 1 space to the right

Multiplying by 100 – decimal place 2 space to the right

Multiplying by 1000 – decimal place 3 space to the right

**Example:** Calculate 327 \times 100

Here we need to more the decimal place **2** spaces to the right, writing zeros in any new places created.

After moving the decimal place **2** spaces to the right and add the zeros in the spaces created, this gives the answers 32700

327 \times 100 = 32700

**Skill 2: Dividing by 10, 100, 1000**

When Dividing by 10, 100, 1000 move the decimal place to the left, the same number of places as zeros in the number.

Multiplying by 10 – decimal place 1 space to the left

Multiplying by 100 – decimal place 2 space to the left

Multiplying by 1000 – decimal place 3 space to the left

**Example:** Calculate 1234 \div 1000

Here we need to more the decimal place **3** spaces to the left.

The decimal place is moved three places to the left.

This gives the answer to be 1.234

1234 \div 1000 = 1.234

## Multiplying and dividing by 10, 100, 1000 Example Questions

1. What is 17\times100?

Here we are multiplying by 100 this will mean we move the decimal place 2 places to the right.

17\times100 = 1700

2. What is 219.65\times1000?

Here we are multiplying by 1000 so we must move the decimal place 3 places to the right.

219.65\times1000= 219650

3. What is 3101 \div 100

As we are dividing by 100 we must move the decimal place 2 places to the left.

3101 \div 100 = 31.01

4. What is 12\div1000

As we are dividing by 1000 we must move the decimal place 3 places to the left.

12\div1000= 0.012