Common IGCSE Maths Mistakes (And How Students Can Avoid Them)

One of the most frustrating things about IGCSE Maths is this:
many students lose marks on questions they actually know how to do.

At Breakthrough Maths, we see this constantly. Students understand the topic, feel confident leaving the exam, and then come back disappointed with the result. Not because the paper was unfair, but because of small, repeatable mistakes that quietly eat away at marks.

The good news?
Most IGCSE Maths mistakes are predictable and fixable once you know what to look for.

Mistake 1: Poor Exam Technique, Not Poor Maths

This is the biggest one, by far.

Many students focus almost entirely on learning content. They revise formulas, practise topics, and assume that knowing the maths is enough. In IGCSE exams, it often isn’t.

Marks are awarded for how an answer is presented, not just the final number. Students regularly lose marks by skipping steps, not showing working clearly, or misinterpreting what the question is actually asking.

At Breakthrough Maths, we teach exam technique alongside content from day one. Students learn how examiners think, where method marks are given, and how to structure answers properly under time pressure.

Mistake 2: Rushing Easy Questions

Another very common IGCSE Maths mistake is assuming early questions are “guaranteed marks” and rushing through them.

This is where careless errors creep in. Sign mistakes, incorrect substitutions, copying numbers incorrectly, all small things, but they add up quickly.

Students often feel they need to save time for the harder questions later on. Ironically, this approach usually costs them more marks than it saves. Slowing down slightly on the first half of the paper often leads to a higher overall score.

Learning how to pace an exam properly is a skill, and like any skill, it can be trained.

Mistake 3: Weak Algebra Foundations

Algebra sits underneath almost everything in IGCSE Maths. When students struggle with algebraic manipulation, it shows up everywhere: equations, functions, trigonometry, even word problems.

Many students can follow worked examples but freeze when the question looks slightly different. This usually points to shaky foundations rather than lack of effort.

At Breakthrough Maths, we don’t just push students through harder questions. We step back, identify the exact algebra gaps, and rebuild them properly so the same mistakes don’t keep repeating. You can watch a video on how we simplify algebra here.

Mistake 4: Misreading the Question

This sounds obvious, but it’s incredibly common.

Students read quickly, spot a familiar-looking question, and jump straight into a method they recognise, without fully processing what’s being asked. As a result, they solve the wrong problem correctly and still lose marks.

This is especially common with:
• Worded questions
• Multi-part questions
• “Hence” or “Show that” questions

Training students to slow down, underline key information, and identify command words makes a huge difference.

Mistake 5: Not Using Past Papers Properly

Doing past papers is essential for IGCSE Maths, but many students don’t use them effectively.

They either:
• Do too many papers without reviewing mistakes properly, or
• Avoid timed conditions altogether

Past papers aren’t just practice; they’re diagnostic tools. Every mistake should point to a specific gap or habit that needs fixing.

At Breakthrough Maths, past paper work is structured and reviewed carefully, so students learn from mistakes rather than repeating them. We also encourage our students to use the Blurting Method, which has been proven to be one of the most effective techniques for improving recall and storing information in long-term memory.

Why These Common IGCSE Maths Mistakes Keep Happening

Most common IGCSE Maths mistakes don’t come from laziness or lack of ability. They come from:
• Poor exam habits
• Gaps that were never addressed
• Lack of clear feedback

Once students understand this, maths becomes far less stressful. Progress feels controlled instead of chaotic.

Final Thoughts

If your child keeps making the common IGCSE Maths mistakes, it’s not a sign they “can’t do maths”. It’s a sign they need clearer guidance, better exam strategy, and targeted support.

At Breakthrough Maths, we focus on fixing the habits that cost marks, not just teaching more content. When those habits change, grades usually follow.

Struggling with common IGCSE Maths mistakes?
Join our waitlist for our 6 week revision course starting on the 2nd of February or learn more about what Breakthrough Maths has to offer here.

Thanks,
TJ