Problem sums are the most challenging part of PSLE Math. They combine multiple concepts and require strategic thinking. This guide breaks down how to approach any problem sum systematically.
The Problem With Problem Sums
Many students can solve calculation questions but struggle with word problems because they:
- Don’t know where to start
- – Can’t identify the relevant information
- – Choose the wrong method
- – Make careless mistakes
The 5-Step Approach
Step 1: Read And Understand
Read the question at least twice. Identify what you’re asked to find. Underline key information.
Step 2: Identify The Given Information
List out what you know:
- Numbers and quantities
- – Relationships (more than, less than, times as many)
- – Fractions and percentages
- – Any other conditions
Step 3: Choose A Strategy
Based on the information, decide which method to use:
- Model drawing
- – Algebra
- – Unit method
- – Working backwards
- – Guess and check
Step 4: Solve Systematically
Work through your chosen method step by step. Show all working clearly.
Step 5: Check Your Answer
Does your answer make sense? Does it satisfy all conditions in the question?
Common Problem Sum Types
- Before-And-After Problems
- Something changes. Track quantities before and after the change.
- Strategy: Draw models or use the unit method.
2. Part-Whole Problems
A whole is divided into parts with different fractions or ratios.
Strategy: Make parts equal using common denominators or units.
3. Comparison Problems
Compare two or more quantities.
Strategy: Draw comparison models.
4. Rate Problems
Something happens repeatedly over time or quantity.
Strategy: Find the rate, then apply it.
5. Fraction/Percentage Problems
Quantities are described in fractions or percentages.
Strategy: Convert to the same format, find the base.
Worked Example
Tom had some marbles. He gave 1/3 of them to Jerry. Then he bought 24 more marbles. He now has 48 marbles. How many marbles did Tom have at first?
Step 1: What are we finding? Initial marbles.
Step 2: Given information:
- Gave away 1/3
- – Bought 24 more
- – Ended with 48
Step 3: Strategy – Work backwards
Step 4: Solve:
Before buying 24: 48 – 24 = 24
Before giving 1/3 away, he had 2/3 left = 24
So 1/3 = 12
Original = 36
Step 5: Check:
36 – 12 (1/3 given) = 24
24 + 24 (bought) = 48 ✓
Practice Tips
Start Simple: Master basic types before combining them.
Time Yourself: Build speed gradually.
Review Mistakes: Understand why you got it wrong.
Practise Daily: 3-5 problem sums daily builds proficiency.
How Ace Scorers Can Help
Our PSLE Math programme covers all problem sum types with structured practice. Students learn to recognise patterns and apply strategies automatically.
Contact us for a trial lesson and watch your child’s problem-solving skills transform.
Ace Scorers – Nurturing Minds, Crafting Achievers
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