X Tables
Problem Solving

Spot the mistake tasks

Use incorrect solutions as a safe way to develop reasoning.

Quick answer

Spot the mistake tasks help you find errors in maths problems and fix them, which makes you better at thinking carefully and solving problems.

Learning outcome

By the end of this page, you will be able to find mistakes in maths problems and explain what went wrong – so you can fix them and become a better problem solver. Success signs:
  • You can spot when a calculation is wrong
  • You can explain why the answer is wrong
  • You can fix the mistake and give the right answer
  • You can think carefully about how to check your own work

Why this matters

Spot the mistake tasks are like detective work in maths. They help you think more carefully and notice if something doesn’t make sense. This skill is useful for:
  • Tests and homework
  • Everyday life, like checking your pocket money or sharing snacks
  • Playing games where you need to count or solve puzzles
  • Building better habits for checking your work
When you learn to find mistakes, you start to understand how maths works better. It’s not just about getting the right answer – it’s about understanding why it’s right or wrong.

How it works

Finding mistakes in maths is a skill you can learn, just like learning to ride a bike or tie your shoes.
  1. Look carefully at the problem and the answer given
  2. Think about what the question is asking – is it addition, subtraction, multiplication, or division?
  3. Work out what the correct answer should be by doing the maths yourself
  4. Compare your answer with the one given – if they don’t match, there’s a mistake
  5. Explain what went wrong – was it a calculation error, or did someone misunderstand the question?

Examples you can see

Here are some examples of spot the mistake tasks to help you understand. Example 1: Simple Addition

Problem: 5 + 3 = 8

Is this correct? Let’s check:

  • 5 + 3 = 8
  • But 5 + 3 = 8 is actually correct!

So this one is not a mistake.

Example 2: Simple Subtraction

Problem: 10 – 4 = 6

Is this correct?

  • 10 – 4 = 6
  • But 10 – 4 = 6 is also correct!

This one is also not a mistake.

Example 3: Mistake in Addition

Problem: 7 + 5 = 11

Is this correct?

  • 7 + 5 = 12
  • But the answer says 11
  • So this is a mistake!

Correct answer: 7 + 5 = 12

Example 4: Mistake in Multiplication

Problem: 6 × 4 = 24

Is this correct?

  • 6 × 4 = 24
  • This is correct!

So this one is not a mistake.

Example 5: Mistake in Division

Problem: 15 ÷ 3 = 4

Is this correct?

  • 15 ÷ 3 = 5
  • But the answer says 4
  • This is a mistake!

Correct answer: 15 ÷ 3 = 5

Try it as a mini adventure

Adventure: The Mystery of the Missing Numbers

You are a detective and your mission is to find the mistake in each of these maths problems. You have a treasure map that shows clues – but only if you find the errors!

Clue 1: 8 + 7 = 14

What’s wrong here?

  • 8 + 7 = 15
  • So the mistake is that it says 14 instead of 15

Clue 2: 9 × 6 = 54

Is this correct?

  • 9 × 6 = 54
  • This is correct – no mistake here!

Clue 3: 12 ÷ 4 = 3

Is this correct?

  • 12 ÷ 4 = 3
  • This is correct – no mistake!

Clue 4: 10 – 6 = 5

What’s wrong here?

  • 10 – 6 = 4
  • So the mistake is that it says 5 instead of 4

Great detective work! You found all the mistakes and fixed them. Now you’ve earned a gold star for your problem-solving skills!

Common mistakes

  • Mistake: Thinking that 12 ÷ 3 = 4, but then writing 12 ÷ 3 = 5
  • Why it happens: Confusing the answer with another number
  • Fix: Double-check the division by multiplying the answer back
  • Mistake: Adding 6 + 7 and getting 13 instead of 12
  • Why it happens: Not counting carefully or using fingers incorrectly
  • Fix: Count on from the larger number or use a number line
  • Mistake: Seeing 3 × 5 = 15, but then thinking 3 × 5 = 10
  • Why it happens: Confusing multiplication with addition
  • Fix: Use repeated addition or draw groups to check
  • Mistake: Subtracting 9 – 4 = 5, but writing 9 – 4 = 6
  • Why it happens: Not checking the subtraction carefully
  • Fix: Add the result back to the number you subtracted to check

Parent and carer guide

As a parent or carer, you can help your child with spot the mistake tasks in these ways:

  • Encourage careful reading – ask your child to read the question twice
  • Ask them to explain – “Why do you think that’s wrong?”
  • Let them check their own work – this builds confidence and independence
  • Use real-life examples – like sharing snacks or counting toys
  • Don’t rush – take time to think through each step together

Remember, it’s normal for children to make mistakes – they’re part of learning. Keep the tone positive and encouraging. If your child gets frustrated, take a break and try again later.

Practice questions

  1. Problem: 4 + 6 = 10. Is this correct? Why or why not?
  2. Problem: 8 × 3 = 24. Is this correct? Why or why not?
  3. Problem: 12 ÷ 2 = 6. Is this correct? Why or why not?
  4. Problem: 7 – 3 = 5. Is this correct? Why or why not?
  5. Problem: 5 × 9 = 45. Is this correct? Why or why not?

Answers:

  1. Yes, 4 + 6 = 10 is correct
  2. Yes, 8 × 3 = 24 is correct
  3. Yes, 12 ÷ 2 = 6 is correct
  4. No, 7 – 3 = 4, not 5
  5. Yes, 5 × 9 = 45 is correct

FAQ

What is a spot the mistake task?

A spot the mistake task is when you look at a maths problem and see if the answer is right or wrong, then explain what went wrong.

Why should I do spot the mistake tasks?

They help you think more carefully and check your work. They also make you better at spotting errors in real life, like when checking your shopping or sharing snacks.

Are these tasks hard?

No, they are designed to be fun and helpful. Start with simple problems and work your way up!

How can I practice at home?

You can use everyday situations like counting toys, checking your pocket money, or sharing food. Ask “Is this right?” and then check it together.

Can I make my own spot the mistake problems?

Yes! You can make up problems with mistakes and challenge a friend or family member to find them.