Edexcel IGCSE Mathematics 4MA1: Frequent mistakes

Pearson Edexcel Principal Examiner Feedback for Mathematics 4MA1 (and 4MB1) highlights recurring topic-specific errors and general exam technique issues. Avoiding these protects your marks.

General exam technique

Miscopying and misreading

Students frequently lose marks by miscopying numbers from questions and misreading their own handwriting. Examiners cannot credit what they cannot read.

Fix: Write clearly. Check figures when copying. Re-read your answer.

Not showing all working

Many fail to show all working stages, particularly when using calculators. Method marks are awarded for correct steps—no working means one error can cost all marks.

Fix: Show every step. Write formula. Substitute. Calculate. Answer.

Topic-specific errors

Trigonometry

Students were less successful with trigonometry questions. Wrong ratio choice; missing sides; incorrect angle mode (degrees vs. radians).

Fix: Identify the sides (opp, adj, hyp). Choose correct ratio. Check calculator mode (DEG).

Inequalities from graphs

Writing inequalities from graphs proved challenging. Wrong inequality direction; wrong boundary (strict vs. non-strict).

Fix: Shaded region = satisfies inequality. Dashed line = strict (<, >). Solid = ≤, ≥.

Ratios in areas and volumes

Using ratios in area and volume contexts caused difficulties. Linear scale factor vs. area (k²) vs. volume (k³).

Fix: Area scale factor = (linear scale factor)². Volume = (linear scale factor)³.

Probability and conditional probability

Finding probabilities in context and applying conditional probability (P(A|B) = P(A∩B)/P(B)) proved challenging.

Fix: “Given that” = conditional. Use formula. Check “exactly one” vs. “at least one”.

Circle theorems

Students struggled with circle theorem questions. Wrong theorem; incomplete reasoning.

Fix: Learn each theorem. Angle at centre = 2 × angle at circumference. Angle in semicircle = 90°. Tangent perpendicular to radius.

Arithmetic sequences

Both identifying and applying arithmetic sequence formulas caused problems. Some confused nth term formula with sum formula.

Fix: nth term: a = a₁ + (n−1)d. Sum: S = n/2(a + l) or n/2(2a + (n−1)d).

Algebra manipulation

Later algebra questions requiring manipulation (expanding, factorising, solving) were found difficult.

Fix: Show steps. Expand brackets. Collect terms. Factorise fully.

Reverse percentages

Reverse percentage problems in context caused difficulty.

Fix: Original × (1 + r/100) = new. So original = new ÷ (1 + r/100). Divide by new value, not original, when finding original.

Partial factorisation

In factorisation questions, some gave partial factorisation rather than fully factorised answers.

Fix: Factorise fully. Check for common factors. e.g. 2x² + 4x = 2x(x + 2).

Indices laws

Multiplying powers instead of adding them; dividing powers instead of subtracting them.

Fix: aᵐ × aⁿ = aᵐ⁺ⁿ. aᵐ ÷ aⁿ = aᵐ⁻ⁿ.

Graph instructions

Not following instructions to find solutions “by drawing a suitable straight line”. Using algebra when graphical method was required.

Fix: Read the rubric. If “by drawing”, draw the line. Use graph to find intersections.

Foundation tier: 3D shapes

Naming 3D shapes and counting hidden edges on diagrams proved challenging.

Fix: Learn names (cube, cuboid, prism, pyramid). Count all edges.

Percentage problems

Dividing by the new value instead of the original when finding percentage change. Forgetting to adjust final answers (e.g. subtract required amounts).

Fix: % change = (new − original)/original × 100. Check what the question asks for.

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Based on Pearson Edexcel IGCSE Mathematics 4MA1 Principal Examiner Feedback (2021–2024).