Primary 6 Maths: Algebra
PSLE algebra is deliberately simple — one variable, no formal equations — but its notation trips many P6 students. What the syllabus actually requires, with worked examples.
Most schools typically cover this topic in Term 2, around weeks 1–3 — though every school sets its own sequence.
Primary 6 algebra is the smallest big topic in the syllabus. The MOE scope is deliberately narrow: one unknown, expressions like 2y + 3, evaluating by substitution, and simplifying by collecting terms. There are no simultaneous equations, no expanding brackets beyond a single multiplier, no factorisation.
So why do children lose marks on it? Notation. Algebra asks a P6 student to accept that 2y means "2 × y", that y + y + y collapses to 3y, and that a letter can stand for any number. Children who miss that shift try to get rid of the letter — usually by inventing a value for it.
The mistakes to watch for
- 3y read as "thirty-something". Children fresh from place value sometimes treat 3y like a two-digit number. 3y means 3 × y, full stop.
- Collecting unlike terms. 5a + 7 − 2a simplified to 10a — folding the 7 into the a-terms. Only like terms combine: 5a + 7 − 2a = 3a + 7.
- Substituting into the wrong expression. Evaluating 2y + 3 at y = 4 as 2 × (4 + 3) = 14 instead of 8 + 3 = 11. Order of operations still rules.
- Dropping units in cost problems. If a pen costs $y, three pens cost $3y — the dollar sign travels with the expression.
Example question — expressions from a story
Try it: build the expression, then evaluate
A pen costs $y. A book costs $3 more than 2 pens.
(a) Express the cost of the book in terms of y.
(b) If y = 4, find the total cost of one pen and one book.
Show the worked solution
(a) Two pens cost $2y, so the book costs $(2y + 3).
(b) When y = 4: pen = $4; book = 2 × 4 + 3 = $11.
Total = 4 + 11 = $15.
Try it: simplify
Simplify 5a + 7 − 2a − 3.
Show the worked solution
Collect the a-terms: 5a − 2a = 3a.
Collect the numbers: 7 − 3 = 4.
Answer: 3a + 4.
Check with a = 2: original gives 10 + 7 − 4 − 3 = 10; simplified gives 6 + 4 = 10. ✓
How to practise this topic
Algebra is the rare P6 topic where a small amount of well-chosen practice closes the gap quickly — the syllabus surface is small. Prioritise translating stories into expressions (the exam's favourite move) and substituting values with correct order of operations. A useful self-check habit: after simplifying, substitute a small number into both versions and confirm they match.
What this topic covers
In the MOE syllabus, Primary 6 Algebra (P6-M-06) includes:
- Simple algebraic expressions
- Simplifying algebraic expressions
- Evaluating algebraic expressions
- Solving simple equations (linear)
- Forming equations from word problems
- Algebraic word problems
Before this topic
These topics feed into Algebra — if this one wobbles, check them first: Primary 6 Whole Numbers (All Operations) · Primary 6 Fractions · Primary 6 Decimals.
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