The student counted only 1 small division above the 200 ml mark. Each division = 25 ml, so 1 division above 200 ml gives 200 + 25 = 225 ml. The water is at the 3rd division: 200 + 3 × 25 = 275 ml.
PRIMARY 3 · MATHEMATICS
Volume of Liquid
Top 5 mistakes
Ranked by how often they appear across 32 MOE-aligned practice questions in our archive.
The student counted only 2 small divisions above the 200 ml mark instead of 3. Each division = 25 ml, so 2 divisions above 200 ml gives 200 + 50 = 250 ml. The water level is at the 3rd division: 200 + 75 = 275 ml.
The student read the nearest labelled mark (300 ml) without counting the smaller divisions between 200 ml and 300 ml. Each small division between 200 ml and 250 ml represents 25 ml, and the water is 3 divisions above 200 ml, giving 200 + 75 = 275 ml.
Treated 2 L as only 1 L (forgetting the bottle holds 2 L, not 1 L): 1000 + 450 = 1450 ml, then made a small slip 1500 - 1450 = 50 ml. Used the wrong number of litres.
Forgot to add the 450 ml part of the bottle volume: used 2 L = 2000 ml only, then mis-subtracted 2000 - 1500 = 500, mis-recorded as 550.
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