Does this sound familiar? You read a question, pick out the numbers, do the calculation, and get an answer. You feel confident. But then you get your paper back and see a big red “X”.

Why? Because you calculated the total number of fruits, but the question asked for the difference between apples and oranges.

This is the #1 reason students lose marks in PSLE Math Paper 2. It’s not an “intelligence” problem; it’s a “decoding” problem. Today, we’re going to fix it with a strategy called C.U.B.E.S.

What is C.U.B.E.S.?

C.U.B.E.S. is a simple checklist to make sure you never miss a clue in a word problem.

• Circle the numbers
• Underline the question
• Box the keywords
• Eliminate extra information
• Solve and Check

Let’s break it down step-by-step with a real example.

The Strategy in Action

Imagine you see this question in your paper:

Primary 6 Class A has 38 students. Mrs Tan bought a bag of 150 candies. She gave 3 candies to each student. How many candies did she have left?

If you rush, you might just do $150 \div 3$ or $150 - 38$. Both are wrong. Let’s use C.U.B.E.S.

Step 1: C - Circle the Numbers

First, find every number in the question and circle it.

“Primary 6 Class A has 38 students. Mrs Tan bought a bag of 150 candies. She gave 3 candies to each student. How many candies did she have left?”

Step 2: U - Underline the Question

This is the most critical step. What are you actually trying to find?

“Primary 6 Class A has 38 students. Mrs Tan bought a bag of 150 candies. She gave 3 candies to each student. How many candies did she have left?”

Now your brain knows the goal: Find the remainder or leftover. Not the total given away, but what is left.

Step 3: B - Box the Keywords

Keywords tell you which operation to use ($+, -, \times, \div$).

“Primary 6 Class A has 38 students. Mrs Tan bought a bag of 150 candies. She gave 3 candies to each student. How many candies did she have left?”

• “to each”: usually implies multiplication (groups of items).
• “left”: usually implies subtraction (finding a remainder).

Step 4: E - Eliminate Extra Information

Sometimes questions throw in useless details to confuse you.

“Primary 6 Class A has 38 students. Mrs Tan works hard. She bought a bag of 150 candies…”

Okay, this example didn’t have much clutter, but longer problem sums often have sentences about the weather or who is friends with whom. Cross it out! If it doesn’t help you solve the math, it’s just noise.

Step 5: S - Solve and Check

Now we build the equation based on our clues.

1. Find total given away: 38 students $\times$ 3 candies each = 114 candies.
2. Find leftover: 150 total - 114 given = 36 candies left.

Check: Does 36 make sense? Yes, it’s less than 150. If you got 450 (using multiplication instead of subtraction), you’d know something was wrong immediately.

Why C.U.B.E.S. Works

In the high-pressure environment of the PSLE exam hall, your brain tries to take shortcuts. It sees “150” and “3” and wants to divide.

C.U.B.E.S. forces your brain to slow down during the reading phase so you can speed up during the solving phase. It prevents the dreaded “careless mistake” of answering the wrong question.

Practice: Try it yourself

Here is a trickier one. Try applying C.U.B.E.S.

Summary

Next time you see a long, scary word problem, don’t panic. Just write C.U.B.E.S. at the top of your paper and start decoding.

1. Circle numbers
2. Underline the question
3. Box keywords
4. Eliminate clutter
5. Solve & Check

It takes 10 extra seconds to read, but it saves you the 5 marks you would have lost.