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Maths Games

Maths magic tricks

Use arithmetic patterns to perform simple number tricks and explain why they work.

Quick answer

Maths magic tricks work because of patterns and rules in numbers that you can use to surprise and amaze your friends and family. You don’t need any special powers – just a bit of maths knowledge!

Learning outcome

By the end of this page, you will be able to use simple maths patterns to perform number tricks that look like magic, and you will understand why they work.

Why this matters

Maths magic tricks help you see how numbers work together in fun and surprising ways. They make learning maths more exciting and help you understand patterns and rules. These tricks also build your confidence in maths and show how useful numbers are in everyday life.

How it works

Maths magic tricks use simple number rules and patterns. Here’s how to do one:
  1. Think of a number (any number you like)
  2. Double it
  3. Add 10
  4. Divide by 2
  5. Take away your original number
  6. You will always get 5!

Examples you can see

Let’s try this trick with the number 7:
  1. Start with 7
  2. Double it: 7 × 2 = 14
  3. Add 10: 14 + 10 = 24
  4. Divide by 2: 24 ÷ 2 = 12
  5. Take away your original number: 12 – 7 = 5
Try it with 3:
  1. Start with 3
  2. Double it: 3 × 2 = 6
  3. Add 10: 6 + 10 = 16
  4. Divide by 2: 16 ÷ 2 = 8
  5. Take away your original number: 8 – 3 = 5
Try it with 12:
  1. Start with 12
  2. Double it: 12 × 2 = 24
  3. Add 10: 24 + 10 = 34
  4. Divide by 2: 34 ÷ 2 = 17
  5. Take away your original number: 17 – 12 = 5
No matter what number you start with, you will always get 5 at the end. That’s the magic!

Try it as a mini adventure

Adventure: The Magic Number Challenge You are a detective who must solve a mystery. A wizard has left a message with a secret number trick. The message says:
  1. Think of any number
  2. Multiply it by 3
  3. Add 6
  4. Divide by 3
  5. Take away your original number
The wizard says the answer will always be 2. Can you prove it? Try it with 4:
  1. Start with 4
  2. Multiply by 3: 4 × 3 = 12
  3. Add 6: 12 + 6 = 18
  4. Divide by 3: 18 ÷ 3 = 6
  5. Take away your original number: 6 – 4 = 2
Try it with 10:
  1. Start with 10
  2. Multiply by 3: 10 × 3 = 30
  3. Add 6: 30 + 6 = 36
  4. Divide by 3: 36 ÷ 3 = 12
  5. Take away your original number: 12 – 10 = 2
You’ve solved the wizard’s trick! The answer is always 2.

Common mistakes

  • Mistake: Forgetting to divide by 2 or 3 in the trick.
    Why it happens: You might rush through the steps.
    Fix: Slow down and double-check each step.
  • Mistake: Thinking the trick will work with any number, but you get a different answer.
    Why it happens: You might make a calculation error.
    Fix: Use a calculator or count carefully to check your maths.
  • Mistake: Trying to do the trick without understanding the pattern.
    Why it happens: You might just want to impress others.
    Fix: Learn the maths behind the trick so you can explain it to others.

Parent and carer guide

Parents and carers can help children by:
  • Practising the tricks together and asking the child to explain how they work
  • Using simple examples to show how the maths works
  • Encouraging children to try different numbers and see if the trick still works
  • Helping children write down the steps so they can remember them
  • Letting children be the magician and teach the trick to others

Practice questions

  1. Try this trick with 8:
    1. Start with 8
    2. Multiply by 2
    3. Add 8
    4. Divide by 2
    5. Take away your original number
    What answer do you get?
    Answer: 4
  2. Try this trick with 5:
    1. Start with 5
    2. Multiply by 4
    3. Add 12
    4. Divide by 4
    5. Take away your original number
    What answer do you get?
    Answer: 3
  3. Try this trick with 11:
    1. Start with 11
    2. Multiply by 5
    3. Add 15
    4. Divide by 5
    5. Take away your original number
    What answer do you get?
    Answer: 3
  4. Try this trick with 15:
    1. Start with 15
    2. Multiply by 6
    3. Add 18
    4. Divide by 6
    5. Take away your original number
    What answer do you get?
    Answer: 3
  5. Try this trick with 20:
    1. Start with 20
    2. Multiply by 7
    3. Add 21
    4. Divide by 7
    5. Take away your original number
    What answer do you get?
    Answer: 3

FAQ

What is a maths magic trick?

A maths magic trick is a fun activity that uses number patterns and rules to make it look like magic. The trick works every time because of maths, not magic!

Can I make up my own magic trick?

Yes! Once you know how the tricks work, you can create your own. Try changing the numbers or the steps and see what happens.

Are these tricks good for learning?

Yes! These tricks help children see how numbers work together and build confidence in maths. They also show how useful and fun maths can be.

Do I need to be good at maths to do these tricks?

No! These tricks are designed to be fun and easy to learn. Even if you're not confident with maths, you can still do these tricks and enjoy them.

How can I use these tricks with my child?

You can practice the tricks together, let your child be the magician, or try to figure out how the tricks work. This helps children understand patterns and build their maths skills.