X Tables
Times Table Methods

Why multiplying by one keeps the number

Use one group and one copy to explain the identity property.

Quick answer

When you multiply any number by one, the number stays exactly the same. This is because you're just taking one group of that number, or one copy of it.

Learning outcome

By the end of this page, you will understand that multiplying any number by one gives you the same number back, and you will be able to explain this using groups and real-life examples. Success signs:
  • You can show that 5 × 1 = 5 by using objects
  • You can explain why 12 × 1 = 12 using a story
  • You can find examples of multiplying by one in your everyday life
  • You can solve problems where you multiply by one

Why this matters

This idea is important because it helps you understand how multiplication works. It's the first step in learning multiplication facts, and it shows that multiplying by one is like doing nothing to your number – it stays exactly the same. This is called the identity property of multiplication. It's like having a magic number that keeps your number safe and unchanged. This concept also helps you in more complex maths later, like working with fractions, algebra, and equations. Knowing that 1 × anything = anything helps you solve bigger problems with more confidence.

How it works

Multiplying by one means you have one group of a number, or one copy of it. Let’s break it down:
  1. Think of your number as a group of objects.
  2. When you multiply by one, you take just one of those groups.
  3. So, you still have all the objects you started with.
For example, if you have 3 apples and you take 1 group of 3 apples, you still have 3 apples.

Examples you can see

Let’s look at some clear examples:
Multiplication What it means Visual example
1 × 2 One group of 2 2 objects in one group
1 × 5 One group of 5 5 objects in one group
1 × 10 One group of 10 10 objects in one group
1 × 12 One group of 12 12 objects in one group
Here’s how it looks with real-life objects:
  • You have 4 toy cars. If you take 1 group of 4 toy cars, you still have 4 toy cars.
  • You have 7 stickers. If you take 1 group of 7 stickers, you still have 7 stickers.
  • You have 9 blocks. If you take 1 group of 9 blocks, you still have 9 blocks.

Try it as a mini adventure

Adventure: The Magic Number Challenge You are a brave explorer on a quest to find the secret of the Magic Number! You find a mysterious chest with a note that says: "To unlock the chest, you must show that multiplying by one gives the same number." You open the chest and inside are different amounts of your favourite snack – let’s say 6 chocolate coins. Now, you must prove the magic is real:
  1. First, you take 1 group of 6 chocolate coins. How many do you have?
  2. Next, you take 1 group of 10 chocolate coins. How many do you have?
  3. Then, you take 1 group of 12 chocolate coins. How many do you have?
Each time, you still have the same number of chocolate coins you started with! This proves that multiplying by one is magic – it keeps your number safe and unchanged.

Common mistakes

  • Mistake: Thinking that 1 × 5 = 1
    Why it happens: Confusing multiplication with addition.
    Fix: Remember that 1 × 5 means one group of 5, so it's still 5.
  • Mistake: Believing that 1 × 0 = 0 is different from 1 × 5 = 5
    Why it happens: Not understanding that any number multiplied by 1 stays the same.
    Fix: Think of 1 × 0 as one group of zero – which is still zero. But 1 × 5 is one group of 5 – which is still 5.
  • Mistake: Thinking that 1 × 1 = 1 is special
    Why it happens: Not seeing it as a rule that applies to all numbers.
    Fix: Remember that 1 × 1 = 1, but also 1 × 2 = 2, 1 × 3 = 3, and so on.

Parent and carer guide

As a parent or carer, you can help your child understand this concept by:
  • Using everyday items like toys, snacks, or pencils to show groups.
  • Playing a game where you say a number and ask your child to show one group of that many items.
  • Repeating the idea: "One group of 5 is still 5."
  • Encouraging them to say the multiplication out loud: "1 × 7 equals 7."
  • Noticing when they make a mistake and gently reminding them of the rule.
This learning is not about memorising facts, but about understanding that multiplying by one doesn’t change a number. It's a simple but important idea that builds confidence for more complex maths later.

Practice questions

  1. What is 1 × 3?
  2. What is 1 × 8?
  3. What is 1 × 11?
  4. What is 1 × 0?
  5. What is 1 × 12?
Answers:
  1. 1 × 3 = 3
  2. 1 × 8 = 8
  3. 1 × 11 = 11
  4. 1 × 0 = 0
  5. 1 × 12 = 12

FAQ

What does it mean to multiply by one?

It means you have one group of a number. Since there is only one group, the number stays the same.

Is multiplying by one the same as adding one?

No, adding one means you increase the number by one. Multiplying by one means you keep the number exactly the same.

Why is multiplying by one important?

It helps you understand the basic idea of multiplication and is the first step to learning all multiplication facts. It also shows that 1 is a special number in multiplication – it's the identity.

Can I use this with big numbers?

Yes! Whether you multiply 1 × 100 or 1 × 1,000, the answer is always the same number you started with.

Does this work with decimals?

Yes! For example, 1 × 2.5 = 2.5. One group of 2.5 is still 2.5.

Times Table Facts: 1 Times Table

1 × 0 1 × 1 1 × 2 1 × 3 1 × 4 1 × 5 1 × 6 1 × 7 1 × 8 1 × 9 1 × 10 1 × 11 1 × 12
0 1 2 3 4 5 6 7 8 9 10 11 12