Common Mistakes in the IB Mathematics AA HL Exam
Awareness of common errors can help you secure marks that are often lost due to oversight rather than a lack of knowledge. Pay attention to these specific pitfalls during your preparation and in the exam.
Exam Technique Errors
- Not showing sufficient working. Write down every logical step, especially for 'show that' questions. Method marks are awarded even if the final answer is incorrect.
- Misinterpreting command terms. Learn the specific IB definitions. 'Write down' means no calculation is needed, while 'calculate' or 'determine' requires showing work.
- Rounding answers prematurely. Keep intermediate values to their full calculator accuracy. Round only the final answer to three significant figures unless specified otherwise.
- Relying on the calculator for Paper 1. Practice all topics without a calculator. You must be fluent in algebraic manipulation, basic trigonometric values, and differentiation from first principles.
- Forgetting to state assumptions. When using a statistical model like the binomial or normal distribution, explicitly state the assumptions that make the model valid.
- Incorrect vector or set notation. Use arrows for vectors, distinguish between vectors and scalars, and use correct symbols for unions, intersections, and elements.
- Giving a probability greater than 1 or less than 0. Always sense-check your answers in probability questions. An answer outside the range [0, 1] is fundamentally incorrect.