PSLE area and volume questions with worked answers
Area and volume questions test whether your child picks the right formula and feeds it the right measurement. Using the diameter where the radius belongs, or adding a side that sits inside a shape, turns a correct method into a wrong answer.
What the PSLE tests in area & volume
- Area and circumference of circles, semicircles and quarter circles, using π = 3.14, 22/7 or the calculator value
- Area and perimeter of composite figures made of rectangles, triangles and parts of circles
- Area of a triangle as 1/2 × base × height
- Volume of cubes and cuboids, and finding a missing length given the volume
- Water tank problems with litres and cubic centimetres
Where children lose the most marks
- Perimeter of composite figures, where inside lines must be left out
- Circle questions that give the diameter when the formula needs the radius
- Tank problems where water is poured in or out and the new height must be found
A PSLE-style question, worked
A figure is made up of a square of side 14 cm and a semicircle. One side of the square is the diameter of the semicircle. Find the perimeter of the figure. Take π = 22/7.
- Diameter of semicircle = 14 cm
- Curved edge = 1/2 × π × d = 1/2 × 22/7 × 14 = 22 cm
- The side shared with the semicircle is inside the figure, so use 3 sides of the square: 3 × 14 = 42 cm
- Perimeter = 42 cm + 22 cm = 64 cm
Why 86 cm is wrong: The child used 14 cm as the radius: 1/2 × 2 × 22/7 × 14 = 44 cm for the curve, then 44 + 42 = 86 cm. 14 cm is the diameter, so the radius is 7 cm.
Free PSLE area & volume questions with answers
Careless mistakes to watch in area & volume
Left out the units
Your child writes 81 instead of 81 cm². Where the answer line does not print the unit, leaving it out can cost marks. How to make units a habit.
See the fix →Converting units (kg, ℓ, m, cm³)
Your child divides by 100 instead of 1000 when changing cm³ to litres, and the answer is ten times too big. Why it happens and how to fix it.
See the fix →Area and perimeter formulas
Your child forgets the ½ in the triangle area formula, or mixes up area and perimeter. How the PSLE mistake looks and how to fix it at home.
See the fix →Radius and diameter in circles
Your child uses the diameter in the circle area formula and the answer is four times too big. Why it happens in PSLE circles and how to fix it.
See the fix →Questions parents ask
Which value of π should my child use in the PSLE?
The one the question states, usually 3.14 or 22/7. If none is given in Paper 2, use the calculator's π key.
Are circle questions always in Paper 2?
No. Circle questions commonly appear in both papers, with numbers chosen to work out by hand in Paper 1, such as a diameter of 14 cm with π = 22/7.
How can my child get better at composite figure questions?
Trace the outline with a finger before calculating, and mark which lines are inside the shape. Knowbotic has 2,838 practice questions in the 2026 format, so there are plenty of figures to practise on.
See which habits are costing your child marks.
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