Decimals
Change between units by moving the decimal point, then bring both quantities to one unit before calculating.
Your child multiplies and divides decimals by 10, 100, 1000 and multiples such as 40 or 200, without a calculator. The digits move to new places while the decimal point stays still. Your child then uses the same moves to change kilometres to metres, grams to kilograms and back, and finally solves word problems where two units must become one. Read the study guide →
About this chapter
Primary 5 decimals questions multiply and divide decimals by 10, 100, 1000 and their multiples, then use the same moves to convert measurements: kilometres and metres, metres and centimetres, kilograms and grams, litres and millilitres. Word problems that mix two units come last.
Practise by question type: p5 mixed units word problems, p5 unit conversion questions and p5 multiply and divide decimals by 10, 100, 1000.
The order to learn them
Which way does the decimal point move?
7.1 and 7.2
Multiplying, dividing and changing units all depend on the value of each place.
Two units in one problem
7.3
Convert the measurements to the same unit before calculating, then give the answer in the unit asked for.
The number tells you where a question type sits in this chapter, not what your child needs to learn first. A child who has already met a type in school can practise it without working through the ones above it.
How the end-of-year papers set these questions
Decimal questions appear in every 2025 Primary 5 end-of-year paper.
Most questions are direct calculations or unit conversions. Longer questions place the conversion inside a problem, so the measurements must use the same unit before they can be compared or combined.
Paper 1 often tests the decimal point in one or two steps.
A child may multiply or divide by a multiple of 10, 100 or 1000, or convert one measurement. The answer choices often differ only in the position of the decimal point.
Longer questions make the required unit part of the method.
A length, mass or capacity may be given in two units. The conversion is written before the arithmetic, and the unit requested by the question is written on the final line.
Everything here is modelled against top school papers. Those papers are never reproduced, and every question on this site is original.
How to set out the working clearly
These examples show Mathweave's clear, consistent layout for each method. The layout is informed by the answer keys we reviewed.
- Show the power of 10 before the remaining factor When the divisor is a multiple of 10, 100 or 1000, divide by that power first and then by the remaining factor. Write each result on the same equals chain.
- Write every unit conversion on its own line State the starting measurement, the multiplication or division used to convert it, and the converted measurement. Use that result only on the next line.
- Put both measurements in the same unit before calculating Do not add, subtract or compare the printed numbers while their units differ. Convert one measurement first, then do the arithmetic.
- Write the requested unit on the answer line A correct decimal in the wrong unit does not finish the question. Check the wording of the question and convert the result again when needed.
Questions parents ask
Is this in the Primary 5 syllabus?
Yes. The question types follow the Decimals outcomes in the latest MOE Primary Mathematics syllabus.
Which practice is available now?
All three question types have original practice.
Are the questions from past papers?
We write the questions ourselves rather than copy them from papers. Each chapter is modelled on the types of question that top school papers set. A question may look like one your child has met before because it is the same type.
What does the practice add?
Practice uses different numbers for each question type, shows the working after every attempt and records which types your child can complete independently.
Primary 5 decimal questions by question type
Primary 5 Decimals Study Guide
See the digits slide past a fixed decimal point, then use that move to change units and to solve problems that mix metres and centimetres. Four tap-through steps, worked examples and a five-question check.
Start hereMoving digitsMultiplesChanging unitsTwo unitsOpen the study guide →