Treated each unit as one angle and computed the smallest: 1 unit = 360 / (2 + 3 + 4 + 6) = 24, then took 24 + 36 = 60 by adding the next ratio increment.
PRIMARY 6 · MATHEMATICS
Angles
Top 5 mistakes
Ranked by how often they appear across 18 MOE-aligned practice questions in our archive.
Used the correct angle sum 360 and ratio total 15 (so 1 unit = 24 degrees), but multiplied by 4 (second-largest part) instead of 6: 4 x 24 = 96.
Mistakenly used the angle sum of a triangle (180 degrees) and divided by 15 units to get 12 degrees per unit, then multiplied by the second-largest part 4: 4 x 30 = 120 by inconsistent calculation.
Used 190° instead of 180° as the angle sum (perhaps from an addition slip). The angle sum of a triangle is 180°, not 190°.
Added 47 and 68 and stopped there, thinking that A and B sum to give C. Instead, A + B + C = 180.
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