PSLE Math Fractions and Percentages: The Ultimate Guide for Primary Students

Fractions and percentages appear in almost every PSLE Mathematics paper, either as standalone questions or embedded in word problems. Students who are not fluent with these concepts will struggle throughout the paper. Our PSLE Math tutors at Sophia Education have compiled this ultimate guide to help students master both topics.

Fractions: The 5 Operations You Must Master

• ✓Addition/Subtraction: find LCM, convert to equivalent fractions, then add/subtract numerators
• ✓Multiplication: multiply numerators together and denominators together, then simplify
• ✓Division: multiply by the reciprocal
• ✓Simplification: always simplify fractions to lowest terms
• ✓Mixed numbers: convert to improper fractions before operations

Percentages: Key Concepts and Question Types

PSLE percentage questions typically involve percentage increase/decrease, finding the original value, or comparing two quantities. The most common mistake is confusing "percentage of" with "percentage more than".

• ✓Percentage of a quantity: multiply by the percentage as a decimal
• ✓Percentage increase: new = original × (1 + rate)
• ✓Percentage decrease: new = original × (1 − rate)
• ✓Finding original: divide new value by (1 ± rate)
• ✓Percentage difference: (difference ÷ original) × 100%

Common Mistakes to Avoid

• ✓Using the wrong base for percentage calculations
• ✓Forgetting to simplify fractions in the final answer
• ✓Mixing up "more than" and "as much as" in word problems
• ✓Not converting mixed numbers before multiplying or dividing
• ✓Rounding too early in multi-step problems

Exam Strategy: How to Score Full Marks

For fraction and percentage questions, always show your working clearly. PSLE markers award method marks even if the final answer is wrong. Write each step on a new line, label your working, and check your answer by substituting back into the original problem.