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PSLE Math Formula Sheet (2026)

The definitive reference for PSLE preparation. Covers DST, Circles, and Percentage rules with pedagogical clarity.

This PSLE Math Formula Sheet is a concise, educator-curated reference designed for Primary 6 students preparing for the 2026 PSLE examination. It covers every essential formula across Numbers & Operations, Percentage, Ratio, Speed (DST), Circles, and Geometry — the six pillars of PSLE Paper 1 and Paper 2. Print it, pin it to the study desk, and use it for daily quick-recall drills.

Numbers & Operations

Order of Operations (GEMS): (1) Groupings/Brackets, (2) Exponents/Square roots (if any), (3) Multiplication/Division (left to right), (4) Addition/Subtraction (left to right). Common trap: Adding before multiplying (e.g., 10 - 2 × 3 = 4, not 8 × 3)

Rounding Decimals: Look at the digit to the right of the target place value (0-4 round down, 5-9 round up). E.g., rounding 4.567 to 2 decimal places is 4.57

Fractions of Remainder: 'Spent 1/3 of remainder' means 1/3 × (1 - Fraction spent initially) × Total. Use branching models to visualize the remainder

HCF & LCM: Use prime factorisation or parallel division. Remember: HCF is for grouping items into equal sizes (biggest size possible); LCM is for finding when two events happen together again (earliest time)

Percentage

Finding Percentage: (Part / Whole) × 100%. Always identify the correct 'Whole' (the denominator), especially in comparison questions (e.g., 'more than B' means B is the whole)

Percentage Change: (Increase/Decrease / Original Value) × 100%. Common trap: Dividing by the new value instead of the original value

GST & Service Charge: Price including 9% GST = Original × 1.09. Price with 10% Service Charge + 9% GST = Original × 1.10 × 1.09 = Original × 1.199 (GST is applied to service charge too!)

Discount: Sale Price = Marked Price × (100% - Discount%)

Ratio & Proportions

Unitary Method: Find the value of 1 unit (1u) first. Write statements clearly (e.g., 5u = 150 => 1u = 30)

Constant Total: Used when items are transferred internally (e.g., A gives 10 to B). The total units before and after must be equal. Find the common multiple of the total units

Constant Difference: Used for age word problems. The difference in age between two people never changes. Equalize the difference in units before and after

Constant One Side: Used when only one quantity changes (e.g., A buys more, B remains constant). Keep B's units unchanged before and after

Speed (The DST Triangle)

Speed formulas: Distance = Speed × Time | Speed = Distance ÷ Time | Time = Distance ÷ Speed

Average Speed = Total Distance ÷ Total Time. Common trap: (Speed1 + Speed2) / 2 is mathematically INCORRECT!

Time Conversions: 15 mins = 15/60 = 0.25 hours. 1 hour 12 minutes = 1 and 12/60 = 1.2 hours. Never write 1 hr 12 mins as 1.12 hours!

Common Speed Scenarios: Meeting at a point (total distance covered = distance between them) or catching up (difference in speed × time = head start distance)

Geometry - Circles

Diameter & Radius: d = 2r. Check if the question gives the diameter or radius before applying area/circumference formulas

Circumference = πd or 2πr (Use 22/7, 3.14, or calculator π as specified in the exam paper)

Area of Circle = πr². Common trap: (πr)² or calculating π × d². Always divide diameter by 2 first

Semicircles & Quarter Circles: Area = 1/2 πr² / 1/4 πr². Perimeter of Semicircle = πr + d (must add the straight diameter line unless it's a curve-only perimeter!)

Geometry - Shapes & Solids

Sum of Angles: Triangle = 180°. Quadrilateral/Square/Rectangle/Parallelogram/Rhombus/Trapezium = 360°

Special Triangle Properties: Isosceles Triangle (2 equal sides, 2 base angles equal), Equilateral Triangle (3 equal sides, all angles = 60°)

Area of Triangle = 1/2 × Base × Perpendicular Height. The height must be perpendicular (90°) to the chosen base

Cuboids & Volume: Volume = Length × Breadth × Height. Base Area = Length × Breadth => Volume = Base Area × Height

Total Surface Area: Sum of the areas of all flat faces. For a closed cuboid: 2(LB + LH + BH). For open tanks, do not count the top face!

Frequently Asked Questions

How many formulas are in this PSLE math formula sheet?▾

This sheet covers 35 core formulas across 6 topic areas: Numbers & Operations, Percentage, Ratio & Proportions, Speed (DST), Circles, and Geometry & Solids. These are the formulas that appear most frequently in PSLE Paper 1 and Paper 2.

Is this aligned to the MOE 2026 syllabus?▾

Yes. Every formula is mapped to the MOE 2026 Primary Mathematics syllabus. We update the sheet annually to reflect any syllabus changes.

How should my child use this formula sheet?▾

We recommend printing it and placing it on your child's study desk. Use it as a quick-recall reference during revision — cover the formula, try to recall it, then check. Once your child can recall all 35 formulas without looking, they are exam-ready for the calculation components.

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