These IGCSE International Mathematics 0607 topics consistently produce the lowest scores. Prioritise these in your revision.
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Single-transformation descriptions (especially enlargement with fractional/negative scale factor)
'The transformation is still called an enlargement even though the image is smaller than the original shape. Some called this a reduction, delargement or disenlargement or used shrink. The second area of misunderstanding was that the scale factor is not 3 but rather 1/3 as the lengths in the image are a third the length of the original's lengths.'
Affects: Paper 1, Paper 2, Paper 4
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Standard form — leading digit, power of 10, and rounding
'Many candidates were unsure of how a standard form number is written with many changing the place of the decimal point to have no digit in front or more than one and omitting to multiplying by a power of 10.' Errors include 27.8 × 10² and 278 × 10¹.
Affects: Paper 1, Paper 2, Paper 4
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Circle-theorem language (centre, circumference, reflex angles)
'Words and phrases such as perimeter, edge, top of the circle, middle, origin or triangle were not accepted for circumference, centre or angle.' On the reflex-angle question only a minority gave 210°; most gave 150°.
Affects: Paper 2, Paper 4
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Solving equations using the GDC graphing mode
'Most candidates instead preferred to write a quadratic equation… A few explained that they had used their graphic display calculator but did not draw the relevant graph to gain credit for communication. Candidates are reminded that using an in-built solver receives no credit.'
Affects: Paper 5, Paper 6
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Quadratic-sequence nth term (constant second difference)
'This part was challenging, with only a few candidates reaching the correct answer. Most did not realise the sequence was quadratic, and most of those who offered an nth term wrote a linear expression. Some had realised the second difference was 2 and gave answers of n + 2 or in the form 2n + k.'
Affects: Paper 1, Paper 2, Paper 5, Paper 6
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Reverse percentage (compound depreciation, original price)
'Many candidates reduced the given value by 10% and then by 6%, multiplying by 0.9 and then 0.94 instead of dividing by 1.10 and then by 1.06. Some of the weaker candidates added the two percentages and treated the question as an increase of 16%.'
Affects: Paper 4
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Surds — simplifying √a × √b and rationalising denominators
'A minority of candidates were able to completely simplify the surds. The most common errors came from candidates using incorrect rules of surds. The most common examples included incorrectly simplifying √(a²b) to b√a or √(cd) to c√d.'
Affects: Paper 2
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Modelling — units, accuracy, and stating models as equations
'The model is not precise. So an answer in milliseconds for the time it takes for the hammer to hit the ground is inappropriate and was not credited.' Many candidates also wrote expressions instead of full models with H = … or V = ….
Affects: Paper 6