Division by 10 and 100

Quick answer

When you divide a number by 10, each digit moves one place to the right on the place value chart. When you divide by 100, each digit moves two places to the right. This makes numbers ten or one hundred times smaller.

Learning outcome

By the end of this page, you will be able to divide any whole number by 10 or 100 by moving the digits to the right and understanding how place value changes.

• You can explain what happens to each digit when dividing by 10 or 100
• You can solve division problems like 450 ÷ 10 and 800 ÷ 100
• You can use place value charts to help you divide by 10 and 100
• You can check your answers using multiplication

Why this matters

Division by 10 and 100 is super useful in real life! When you're sharing money, measuring ingredients, or reading maps, you often need to make numbers smaller. For example, if you have £360 and want to share it equally between 10 people, you need to divide by 10. If you're reading a map and the scale says 1 cm = 100 m, you're working with numbers that are 100 times bigger than what you see on the map. Understanding this helps you solve problems faster and check if your answers make sense.

How it works

Let's imagine you have a number like 456. If you divide it by 10, you make it ten times smaller. Here's how:

1. Look at each digit in the number 456
2. Each digit moves one place to the right on the place value chart
3. The digit in the hundreds place (4) moves to the tens place
4. The digit in the tens place (5) moves to the ones place
5. The digit in the ones place (6) moves to the tenths place (which is a decimal)
6. You might need to add a decimal point if there wasn't one before

When you divide by 100, you move each digit two places to the right. This makes numbers one hundred times smaller.

Examples you can see

Let's work through some examples together:

Here's a visual example using place value charts:

Example 1: Start with 240

After dividing by 10:

So 240 ÷ 10 = 24

Example 2: Start with 800

After dividing by 100:

So 800 ÷ 100 = 8

Try it as a mini adventure

The Great Cake Sharing Challenge!

You're helping your family bake a big cake for a party. The recipe says you need 600 grams of flour. But your mom says she only wants to make a quarter of the recipe. You need to divide the amount by 4. But first, you need to divide by 100 to make it easier to work with. How much flour do you need?

1. Start with 600 grams
2. First, divide by 100 to make it easier to work with: 600 ÷ 100 = ?
3. Now divide that by 4 to find a quarter of the recipe: ? ÷ 4 = ?
4. How much flour do you need?

Let's work it out together:

1. 600 ÷ 100 = 6
2. 6 ÷ 4 = 1.5
3. So you need 1.5 grams of flour

Common mistakes

• Mistake: Thinking that 340 ÷ 10 = 340
  Why it happens: Confusing division with multiplication
  Fix: Remember that dividing by 10 makes numbers smaller, so the digits move right, not left
• Mistake: Forgetting to add decimal points
  Why it happens: Not remembering that when you move digits to the right, they become decimals
  Fix: Always check if your answer needs a decimal point and add it where needed
• Mistake: Moving digits in the wrong direction
  Why it happens: Not understanding that division makes numbers smaller
  Fix: Remember: divide by 10 = move right one place, divide by 100 = move right two places
• Mistake: Not checking answers with multiplication
  Why it happens: Rushing through problems without double-checking
  Fix: After dividing, multiply your answer by 10 or 100 to see if you get back to the original number

Parent and carer guide

Helping your child with division by 10 and 100 is simple and fun!

• What to say: "Let's look at this number and see what happens when we divide by 10. What happens to the digits?"
• What to do: Use place value charts or counters to show the movement of digits
• What to watch for: Your child might forget to add decimal points or move digits in the wrong direction
• What not to worry about: It's normal for children to make mistakes at first. The key is to practice and understand the pattern
• How to help: Practice with real objects like coins or counters, and always check answers with multiplication
• Keep it fun: Turn it into a game where you race to move digits correctly or use a calculator to check answers
• Reinforce: Point out real-life situations where this skill is used, like when sharing money or reading scales

Practice questions

1. What is 560 ÷ 10?
2. What is 7800 ÷ 100?
3. What is 300 ÷ 10?
4. What is 9000 ÷ 100?
5. What is 420 ÷ 10?
6. What is 2500 ÷ 100?
7. What is 800 ÷ 10?
8. What is 1000 ÷ 100?
9. What is 630 ÷ 10?
10. What is 1200 ÷ 100?

Answers:

1. 56
2. 78
3. 30
4. 90
5. 42
6. 25
7. 80
8. 10
9. 63
10. 12

FAQ

What happens when you divide by 10?

When you divide by 10, each digit moves one place to the right on the place value chart. This makes the number ten times smaller.

What happens when you divide by 100?

When you divide by 100, each digit moves two places to the right on the place value chart. This makes the number one hundred times smaller.

How do I know which way to move the digits?

When you divide, the digits always move to the right. Divide by 10 = move right one place, divide by 100 = move right two places.

Why do we need to add decimal points?

When digits move to the right, they become smaller parts of a whole number. For example, when 6 moves from the hundreds place to the tenths place, it becomes 0.6.

Can I use this method for any number?

Yes! This method works for any whole number, no matter how big. Just remember to move the digits the right number of places and add decimal points where needed.