5 Biggest Mistakes IGCSE Combined Science Students Make — and How to Avoid Them

The Biggest Mistakes Students Make in IGCSE Combined Science — and How to Avoid Them

Cambridge IGCSE Combined Science is one of the most popular science courses students take around the world — and for good reason. It covers Biology, Chemistry and Physics in a single qualification, giving learners a strong foundation for further science study. Yet this broad coverage can also make the subject tricky. Many students know the content in pieces, but struggle when it comes to applying it under exam conditions. Below, we break down the 5biggest mistakes IGCSE Combined Science Students Make — and exactly how to avoid them.

🎯 1. Treating Science as Memorisation Instead of Application

One of the biggest pitfalls is approaching IGCSE Combined Science like a fact-recall subject. Students often memorise definitions or lists without learning how to apply concepts to solve problems. In Chemistry, for example, it’s not enough to memorise what an acid is, students must use that knowledge to explain results or predictions. Physics questions often test reasoning about forces, energy and circuits, not just remembering formulas.

How to fix it:

Practice IGCSE Combined Science past papers and ask yourself why answers are correct, not just what they are. Link concepts across Biology, Chemistry and Physics to build flexible thinking.

🧠 2. Ignoring Scientific Vocabulary and Clarity

Science isn’t just about knowing, it’s about communicating clearly. Examiners look for precise language, especially in explanations. Students lose easy marks when they write vague answers like “it moves faster” or “it changes temperature” without specifying how or why that happens in scientific terms.

How to fix it:

Learn key terms and their meanings, and practise writing short, clear explanations in full sentences.

📈 3. Avoiding Graphs, Data and Calculations

Cambridge IGCSE Combined Science includes questions that require:

• Reading graphs
• Interpreting data tables
• Performing calculations (e.g., density, speed, reaction rates)

Students who skip practice on these lose marks early.

How to fix it:

Include graph interpretation and calculation questions in your revision plan. Work with past papers where scientific reasoning is required alongside numerical answers.

🔬 4. Doing Practical Skills Only in Theory

Even when practicals aren’t conducted in class, students are still expected to show understanding of scientific methods — how experiments are designed, what variables matter, and why results occur.

Questions like “Why did the temperature change?” are testing practical insight, not just content recall.

How to fix it:

Practice writing short practical explanations and always think about cause and effect in an experiment, even if you didn’t perform it yourself.

📌 5. Failing to Answer the Question Asked

One of the most common exam mistakes is answering a question you prepared for instead of the question you were asked. This especially shows up in longer, structured responses.

For example:

Explain how changes in concentration affect reaction rate.

Many students describe reaction rate in general terms instead of directly linking concentration to reaction rate.

How to fix it:

Underline or rephrase the question in your own words before you begin writing.

📅 6. EXTRA ONE! Not Practicing with Actual Cambridge IGCSE Combined Science Questions

The structure and wording of Cambridge questions can feel unfamiliar. Guessing what an examiner wants often leads to lost marks.

How to fix it:

Work through past papers and mark schemes — not just worksheets and revision notes. Mark schemes show exactly how marks are awarded.

Success in IGCSE Combined Science isn’t just about knowing facts, it’s about thinking critically, solving problems, interpreting data, and communicating scientific ideas clearly. That’s exactly where Global Tutors can make a real difference.

What Cambridge IGCSE Combined Science Includes

Cambridge IGCSE Combined Science is a single award qualification that brings together essential topics from the three sciences — Biology, Chemistry, and Physics — so that students develop a well-rounded understanding of science, both conceptually and practically.

Biology (Life & Living Systems)

Students cover fundamental biological ideas such as:

• Characteristics and processes of living organisms
• Cell structure and function
• Movement of substances (diffusion, osmosis)
• Nutrition and digestion
• Transport systems in plants and animals
• Gas exchange and respiration
• Coordination and response systems
• Reproduction in plants and mammals

This section helps students understand how living things work and interact with their environment.

Chemistry (Matter & Change)

The chemistry part of the syllabus includes:

• Atomic structure and the periodic table
• Chemical bonding and reactions
• Rates of reaction
• Acids, bases, and salts
• Metals and reactivity
• Electrolysis and energy changes
• Chemical calculations and formulae

Students learn how substances interact and transform, building a foundation for later scientific study.

Physics (Forces, Energy, and the Physical World)

In Physics, topics include:

• Forces and motion
• Energy, work, and power
• Heat transfer and thermal physics
• Waves (including light and sound)
• Electricity and circuits
• Magnetism and electromagnetism
• Atomic and nuclear physics

This component helps students understand the physical principles that govern the world around them.

In addition to topic knowledge, the syllabus emphasises key scientific skills:

• Handling and interpreting data
• Planning and carrying out investigations
• Understanding experimental methods
• Applying mathematical skills in science
• Communicating scientific ideas clearly

These skills help students think like scientists and prepare them for higher-level courses or careers that require critical thinking and problem solving.

🎓 Expert Tutors with Real Cambridge IGCSE Combined Science Experience

Our tutors aren’t general educators, they are experienced in Cambridge IGCSE Combined Science, including Biology,Chemistry and Physics, and know how the exam works, what examiners are looking for, and how students can maximise marks.

Focused Exam Preparation

• Practice with Cambridge-style questions
• Build confidence with data interpretation and calculations
• Master key skills, not just memorise content
• Global Tutors helps students tackle the parts of IGCSE Combined Science that many struggle with most.

Personalised One-to-One Support

Whether your child is aiming for a top grade or needs support to pass with confidence, Global Tutors offers structured, expert help for IGCSE Combined Science.