Top Mistakes Students Make in GCSE Maths (And How to Fix Them)

Every year, I see the same mistakes — and they have nothing to do with intelligence. They are habits, and habits can be changed.

Here are the most common mistakes (and how to fix them fast).

1. Not Showing Working

Students think working is optional. Examiners think working is essential.

Fix: Teach your child the “3-step rule”:

1. Write the formula

2. Substitute numbers

3. Solve and box the answer

4. 
   

Instant mark boosts.

2. Rushing Easy Questions

Students lose marks because they underestimate “simple” questions.

Fix:Tell your child to slow down on:

• FDP

• Ratio

• Area & perimeter

• Basic algebra

• Rounding & estimation

• 
  

These are easy grade boosters.

3. Practising the Wrong Way

Many students watch videos instead of practising.

Fix: Use the “video → example → practice” method: Watch one example, then practise 10 questions.

4. Leaving Blank Answers

Students skip questions they “don’t get.”

Fix: Teach the 1-minute strategy: If your child doesn’t understand after 1 minute, they write something:

• A formula

• A diagram

• A relevant number

Even guesses can earn marks.

5. Not Reviewing Mistakes

The quickest way to improve is to correct what went wrong.

Fix: After every paper:

• Mark

• Identify errors

• Redo mistakes

• Try a similar question

• 
  

Consistent improvement follows.

For personalised support targeting your child's weaknesses, explore my tutoring packages here: EAP Tutoring – GCSE Support.