PSLE average and data questions with worked answers
Average questions turn on one idea: the total equals the average times how many. When a person joins or leaves a group, your child has to work with totals, not compare the two averages.
What the PSLE tests in average & data
- Average as the total divided by the number of items
- Finding the total, or a missing value, from a given average
- Reading and interpreting pie charts, including fractions and percentages of the whole
- Reading tables, bar graphs and line graphs to answer questions
- Problem sums where the average changes when an item is added or removed
Where children lose the most marks
- Questions where someone joins or leaves a group and the new average is given
- Pie charts that give angles or fractions and ask for an actual quantity
- Line graph questions about the greatest increase or decrease between two points
A PSLE-style question, worked
The average mass of 4 boys is 42 kg. When Ravi joins them, the average mass of the 5 boys becomes 43.5 kg. What is Ravi's mass?
- Total mass of 4 boys = 4 × 42 kg = 168 kg
- Total mass of 5 boys = 5 × 43.5 kg = 217.5 kg
- Ravi's mass = 217.5 kg − 168 kg = 49.5 kg
Why 1.5 kg is wrong: The child subtracted the averages, 43.5 − 42 = 1.5. The averages describe different groups, so the totals must be found first: total = average × number of boys.
Careless mistakes to watch in average & data
Average and total
Your child subtracts two averages and gets 2 kg when the answer is 52 kg. Why PSLE average questions trip children up and how to fix it.
See the fix →Calculation slip
Your child uses the right method but slips on the arithmetic, like a missing zero in long division. How to spot calculation slips and cut them down.
See the fix →Questions parents ask
Are pie charts in the PSLE Maths syllabus?
Yes. Reading and interpreting pie charts is part of P6, often together with fractions or percentages of the whole.
Is a calculator allowed for average questions?
In Paper 2, yes. Average questions in Paper 1 use numbers that can be worked by hand.
How do I know if my child has fixed the average mistake?
Look for whether they write the total before anything else. Knowbotic's weekly report for parents shows which habits your child has fixed and which still cost marks.
See which habits are costing your child marks.
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