How to explain word problems in LCM and HCF to your student: Example question for 11+
27 October 2026
Word problems with LCM (Lowest Common Multiple) and HCF (Highest Common Factor) can seem tricky at first. By breaking them down into small, simple steps, your child can learn to spot what the question is really asking and how to solve it using lists of multiples or factors.
LCM and HCF word problem example
Three bells ring at intervals of 4, 6 and 8 minutes. All the bells ring together at 9:00 am. When will they next ring together?
Step 1: Find the LCM (Lowest Common Multiple) of 4, 6 and 8.
Multiples of 4: 4, 8, 12, 16, 20, 24, 28, 32, 36, 40, 44, 48
Multiples of 6: 6, 12, 18, 24, 30, 36, 42, 48
Multiples of 8: 8, 16, 24, 32, 40, 48
Step 2: Find the smallest number that is in all three lists.
The smallest common multiple is 24.
Step 3: Add 24 minutes to 9:00 am.
9:00 am + 24 minutes = 9:24 am
The correct answer is 9:24 am.
Key insight: After working through this example, your child will be able to recognise when to use LCM in a word problem and how to find the answer step by step. Practise similar questions to build confidence and speed for the 11+ exam.
