PSLE decimals questions with worked answers
Most decimals mistakes come down to where the decimal point lands. Your child needs to multiply and divide decimals by hand for Paper 1, and carry decimals through money and measurement problem sums without losing a place.
What the PSLE tests in decimals
- Multiplying and dividing decimals by whole numbers, and by 10, 100, 1000
- Multiplying a decimal by a decimal
- Rounding to a given number of decimal places
- Converting between decimals and fractions
- Money and measurement problem sums in kilograms, litres, metres and dollars
Where children lose the most marks
- Multiplying two decimals by hand and placing the decimal point correctly
- Problem sums mixing units, such as grams with kilograms, before the decimals are worked
- Rounding only the final answer, not each step, when the question asks for 2 decimal places
A PSLE-style question, worked
Ravi bought 3 kg of prawns at $18.45 per kg and 2.5 kg of fish at $9.80 per kg. He paid with a $100 note. How much change did he receive?
- Prawns: 3 × $18.45 = $55.35
- Fish: 2.5 × $9.80 = $24.50
- Total: $55.35 + $24.50 = $79.85
- Change: $100 − $79.85 = $20.15
Why $42.20 is wrong: The child worked 25 × 98 = 2450 for the fish but counted too many decimal places, writing $2.45 instead of $24.50. The total became $57.80 and the change $42.20.
Free PSLE decimals questions with answers
Careless mistakes to watch in decimals
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 →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
Can my child use a calculator for decimals in the PSLE?
Only in Paper 2. In Paper 1 decimals must be multiplied and divided by hand, so the decimal point has to be placed without help.
Are decimals tested as a separate topic in the PSLE?
Decimals commonly appear on their own in short questions and inside money, measurement, percentage and rate problem sums.
How should my child check a decimal answer?
Estimate first. If 2.5 kg of fish at about $10 per kg should cost about $25, an answer of $2.45 is clearly wrong before any marks are lost.
See which habits are costing your child marks.
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