Singapore Math guide to algebra in Primary 6 for families and teachers outside Singapore. What Primary 6 students learn about letters, expressions and simple equations, how Singapore teaches it, and how to practise it at home.
A letter in algebra stands for a number.
That one sentence is the whole of the first step, and it is the step most children rush.
In Singapore Mathematics, algebra is a Primary 6 topic in the current primary syllabus. Students use a letter to represent an unknown number, write and simplify simple expressions, find their values by substitution and solve simple linear equations.
The work is deliberately limited at this stage. Secondary 1 then adds brackets, wider notation, formulae and a fuller study of linear equations.
This guide is useful for families and teachers who want to:
- understand what Singapore expects at Primary 6;
- teach early algebra at home in a clear sequence;
- prepare a child who is moving into a Singapore school; or
- support a student using Singapore Math materials in another country.
Quick facts
Level: Primary 6 (Standard Mathematics)
Strand: Number and Algebra
Official source: MOE Primary Mathematics Syllabus, the 2021 syllabus first examined at PSLE in 2026
Comes after: Order of Operations and Ratio
Leads to: Algebraic Expressions and Linear Equations
What Algebra Means in Primary 6 Singapore Mathematics
At Primary 6, a letter such as n stands for a number we do not yet know, or a number that can change.
If a bag holds n marbles, then 3 bags hold 3 × n marbles, written 3n. Two more marbles than one bag is n + 2.
An expression such as 3n + 2 is a calculation waiting for a number. When n = 5, it has the value 3 × 5 + 2 = 17.
An equation such as 3n + 2 = 17 says that the expression has one particular value. Solving it means finding the number n must be.
This page keeps to the Primary 6 syllabus job. For the wider move from models and arithmetic to symbols, read the Singapore Math to Algebra guide.
Where Algebra Sits in the Singapore Syllabus
In the current primary syllabus, algebra appears only at Primary 6.
At Primary 6, students learn:
- using a letter to represent an unknown number;
- simple algebraic expressions;
- simplifying simple linear expressions, excluding brackets;
- evaluating expressions by substitution; and
- simple linear equations involving whole-number coefficients only.
Algebra does not appear in Foundation Mathematics.
| Level | What students do with algebra |
|---|---|
| Primary 6 | Letters for unknowns, simple expressions, simplifying without brackets, substitution, simple linear equations with whole-number coefficients |
| Secondary 1 | Letters for numbers, notation such as ab, a/b and 3(x + y), evaluating expressions and formulae, nth term of a pattern, simplifying, brackets and common factors, linear equations in one variable |
| Secondary 2 | Expansion, factorisation, changing the subject of a formula, algebraic fractions, simultaneous equations |
Two limits matter at Primary 6: no brackets when simplifying, and whole-number coefficients in equations. Keep home practice inside them until the ideas are secure.
How Singapore Teaches Algebra in Primary 6
1. Let a letter stand for a number
Start with a situation: a box holds some pencils, and we call the number in the box p. Ask what 2 boxes hold, or 1 box with 3 extra pencils.
2. Write expressions from words
“5 more than p” is p + 5. “5 less than p” is p − 5. “p shared equally among 4” is p ÷ 4, also written p/4. “4 times p” is 4p.
3. Learn the notation
4p means 4 × p. The number is written before the letter and the × sign is left out. p ÷ 4 can be written as the fraction p/4.
4. Simplify by collecting like terms
2p + 5p = 7p, because 2 groups of p and 5 groups of p make 7 groups of p. In 6p + 4 − 2p, only the p terms combine, giving 4p + 4.
5. Substitute to find a value
To find 4p − 5 when p = 6, replace p with 6 and use the order of operations: 4 × 6 − 5 = 19.
6. Solve simple equations
For 4p + 3 = 23, undo the steps in reverse order: 4p = 20, so p = 5. A bar model of 4 equal units and 3 more, making 23, shows the same reasoning.
Children who see a letter as a number find every later step easier. Children who see it as a label, such as “p for pencils”, often make errors they cannot explain.
Worked Examples
Writing and evaluating an expression
Question: A pen costs $p. A book costs $4 more than the pen. Write an expression for the total cost of 3 pens and 1 book. Find the total cost when p = 2.
Step 1. Cost of 3 pens = 3p dollars.
Step 2. Cost of 1 book = p + 4 dollars.
Step 3. Total cost = 3p + p + 4 = 4p + 4 dollars.
Step 4. When p = 2, the total cost is 4 × 2 + 4 = $12.
Check: 3 pens cost 3 × $2 = $6, the book costs $6, and $6 + $6 = $12.
Writing “dollars” after the expression keeps the units clear without needing brackets, which Primary 6 simplifying does not use.
Solving a simple equation
Question: Ali thinks of a number, multiplies it by 3 and then adds 7. The answer is 34. What is the number?
Step 1. Let the number be n. Then 3n + 7 = 34.
Step 2. Subtract 7 from both sides: 3n = 27.
Step 3. Divide both sides by 3: n = 9.
Check: 3 × 9 + 7 = 27 + 7 = 34.
A bar model helps here. Draw 3 equal bars for 3n, add a short bar for 7, and label the whole as 34.
Common Mistakes
- Treating a letter as a label. A child reads 3a as “3 apples” rather than “3 times a number”. Fix: say “a stands for the number of apples” or “the cost of one apple”.
- Combining unlike terms. A child simplifies 3n + 2 to 5n. Fix: only terms with the same letter combine. 3n + 2 is already simplest.
- Writing the subtraction backwards. “5 less than n” is written 5 − n. Fix: test with a number. If n = 8, 5 less than 8 is 3, which is 8 − 5.
- Joining digits when substituting. With n = 4, a child writes 3n as 34. Fix: write the × sign back in: 3 × 4 = 12.
- Ignoring the order of operations. With n = 5, a child works out 2 + 3n as 5 × 5 = 25. Fix: multiply first: 2 + 3 × 5 = 17.
- Doing something to one side only. In 3n + 7 = 34, a child subtracts 7 on the left but not on the right. Fix: say “both sides” at every step and check the answer in the original equation.
Teaching Algebra Outside Singapore
Algebra notation is broadly shared across English-language curricula. A few points are worth knowing.
- Notation. Singapore writes 3n for 3 × n and uses both n ÷ 4 and n/4. Encourage children to read 3n aloud as “3 times n”.
- Brackets. Singapore calls ( ) brackets; US materials often say parentheses. At Primary 6, brackets are not used in simplifying. They come into algebra in Secondary 1.
- Timing. In Singapore’s current syllabus, algebra is a Primary 6 topic. Your local curriculum may introduce it at a different stage, so decide by readiness rather than age. The Singapore Math Grade Levels guide explains why direct conversions are unreliable.
- Prerequisites. Algebra depends on the order of operations, inverse operations and confident mental arithmetic. If those are weak, repair them first.
- Models still matter. The bar model and algebra describe the same relationships. A child who can draw 3 equal bars and 7 more is ready to write 3n + 7.
How to Practise Algebra at Home
A short, regular routine works better than one long weekend session.
- Describe a situation in words and ask the child to write it with a letter.
- Simplify two expressions with like terms and a number, such as 5m + 9 − 2m.
- Substitute one value into two different expressions and compare the answers.
- Solve one equation by undoing the steps, then check it in the original equation.
- Draw a bar model for one equation and match each bar to a term.
- Once a week, turn an earlier word problem into an equation so the child sees the connection.
Ten to fifteen minutes is enough when the work is focused.
Try These
- Write an expression for “8 less than k”.
- Simplify 5m + 9 − 2m + 3.
- Find the value of 6y − 4 when y = 7.
- Solve 5x − 6 = 29.
Answers
- k − 8. Test with k = 10: 8 less than 10 is 2, and 10 − 8 = 2.
- 3m + 12. Combine 5m − 2m = 3m, and 9 + 3 = 12.
- 38. 6 × 7 = 42, and 42 − 4 = 38.
- x = 7. Add 6 to both sides to get 5x = 35, then divide by 5.
What Comes Next
Primary 6 algebra is the first step of a long staircase.
- In Secondary 1, Algebraic Expressions adds brackets, common factors, formulae and the nth term of a pattern.
- In Secondary 1, Linear Equations includes simple fractional equations and forming equations from problems.
- In Secondary 2, Expansion and Algebraic Identities multiplies out brackets.
A student who reads a letter as a number usually finds these later topics far less mysterious.
Frequently Asked Questions
When do Singapore students learn algebra?
In the current primary syllabus, algebra is taught in Primary 6. It continues in Secondary 1 and grows through every later year.
Does Primary 6 algebra include brackets?
No. Simplifying linear expressions at Primary 6 excludes brackets. Using brackets and extracting common factors is Secondary 1 content.
Can Primary 6 equations have fraction or decimal coefficients?
No. Primary 6 equations involve whole-number coefficients only.
Is algebra part of Foundation Mathematics?
No. Algebra does not appear in the Primary 5 or Primary 6 Foundation Mathematics content.
Should my child stop drawing bar models now?
No. Models and algebra support each other. Many students draw a model to see the relationship, then write the equation.
My child can solve equations but cannot write them from words. Why?
Writing expressions from words is a separate skill. Practise short phrases, such as “4 more than n”, before full word problems.
Helpful Reading
- Singapore Mathematics | International Edition: Order of Operations
- Singapore Mathematics | International Edition: Algebraic Expressions
- Singapore Mathematics | International Edition: Linear Equations
- Singapore Math to Algebra | Moving from Models and Arithmetic to Symbols
- Arithmetic to Algebra Dependency | Mathematics Knowledge Warehouse
- Why Algebra Becomes the Language of Secondary Mathematics
- MOE Primary Mathematics Syllabus
- SEAB PSLE Formats Examined in 2026
Algebra in Singapore Mathematics
A letter is a number.
Like terms combine.
Substitute, then follow the order of operations.
Undo the steps to solve.
Taught this way, algebra stops being a new language with strange rules.
It becomes arithmetic written in general.
That habit carries a student from Primary 6 into the algebra of secondary school.
Ask Bukit Timah Tutor
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If your child is learning Singapore Mathematics at home, in an international school or in a Singapore school, and you are unsure where to begin with this topic, send us a short message with the student’s level and one example of the work.
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Singapore Mathematics | International Edition is a Bukit Timah Tutor guide series for families and teachers outside Singapore. It is not a textbook and is not affiliated with MOE, SEAB or any publisher. Syllabus details were checked against MOE and SEAB documents in October 2026. Always confirm current requirements with your school.
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