GCSE maths Highest Common Factor HCF & Lowest Common Multiple LCM questions appear on many exam papers and you can download the questions here. There are a couple of different ways of approaching these types of problems, although using a factor tree is the most popular.
Other options would be to use short division … or writing out the highest common factors or lowest common multiples in a straight line. These videos are quite popular on my YouTube channel:
The main things to remember when working with GCSE Highest Common Factor HCF & Lowest Common Multiple LCM questions:
- Make sure you show all your working – the questions are usually worth a few marks so take your time …
- Write the products of each number above each other – shown in the video – it’ll make the HCF / LCM calculations much easier
If you’d like to ask for any more detail, or you’re not sure about anything, please do ask a question in the comments section. I’ll let you know as soon as I’ve posted an answer.
The answer videos are given below and here’s the complete worked answers.
All very best with your studies.
How to work with HCF and LCM – actual exam questions 1 – 7
How to work with HCF and LCM – actual exam questions 8 – 12
Watch these videos on YouTube: