These O Level Mathematics D 4024 topics consistently produce the lowest scores. Prioritise these in your revision.
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Proportionality with multiple variables
Candidates struggled to set up equations involving joint or inverse proportion, particularly when more than two variables were involved.
Affects: Paper 2
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Vector proofs (collinearity)
Candidates found it difficult to prove that three points are collinear using vectors, often failing to show that one vector is a scalar multiple of another.
Affects: Paper 2
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Perpendicular bisector proofs
Questions requiring the equation of a perpendicular bisector were poorly answered, with candidates confusing the midpoint with the gradient relationship.
Affects: Paper 2
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Function notation f(x+5)
Candidates confused f(x) + 5 with f(x + 5), not understanding that f(x + 5) requires substituting (x + 5) everywhere x appears in the function.
Affects: Paper 1
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Cone-from-sector problems
Candidates struggled to connect the arc length of a sector to the circumference of the cone's base, a key relationship in these problems.
Affects: Paper 2
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Histogram frequency density
Many candidates plotted frequency instead of frequency density on histograms, and could not calculate frequency density = frequency ÷ class width.
Affects: Paper 1, Paper 2
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Circle theorem reasoning
Candidates could often find missing angles but failed to name or explain the circle theorem used, losing marks that require geometric reasoning.
Affects: Paper 1, Paper 2
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3D trigonometry
Candidates struggled to identify the correct right-angled triangle within a 3D shape and often applied trigonometric ratios in the wrong plane.
Affects: Paper 2
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Conversion between units of area and volume
The 2025 P22 report notes 'Conversion from m² to cm² proved challenging for many. The most common error was 610, using the linear conversion factor of 100. Other errors involved multiplying or dividing by an incorrect power of 10.' The same paper saw candidates struggle to relate cm³ to litres.
Affects: Paper 2
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Set notation and Venn diagrams
Under the revised 2025 syllabus, set notation was assessed explicitly. Candidates confused A', A ∩ B, A ∪ B', and (A ∪ B)'; many listed elements when asked for the count, or gave the count when asked for a list. Shading the wrong region on a Venn was common.
Affects: Paper 1, Paper 2
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Surds — simplification and rationalising the denominator
New 2025 syllabus content. The s25 P12 report observed candidates using methods like '√175 − √28 = √(175 − 28) = √147' and rationalising errors that introduced unnecessary negative signs, indicating that many were unfamiliar with the convention that surds combine multiplicatively, not additively.
Affects: Paper 1
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Recurring decimal to fraction conversion
New 2025 syllabus content. Candidates frequently misread the dot/bar notation as a terminating decimal (e.g. 0.17 = 0.1777) or wrote answers as decimal-over-integer fractions rather than integer-over-integer. The algebraic method (let x = decimal, multiply by 10^n, subtract) was poorly known.
Affects: Paper 1