## LCM and HCF

The one side worksheet covers

• Finding factors of a number in a systematic way
• Finding multiples of number
• Highest common factor and lowest common multiple of two by ‘common sense’ listing methods
• Finding the prime factors of a number
• Lowest common multiple and highest common factor of two numbers using a systematic method based on a Venn diagram

Simple logic and Venn diagram based questions are no longer on the GCSE or other level 2 syllabuses unfortunately, but a simple Venn diagram provides such an easy way of explaining how to build the HCF and LCM of two numbers that I feel justified in including it.

The prime factors of a positive whole number represent one of the more abstract bits of basic maths, so I find an immediate application helps students see what the prime factors are for, and helps then avoid the confusion between the prime factors and the ‘ordinary’ factors.

I wrote these questions for homework, but they could be used in a workshop setting or as a quick check at the start of a lesson. Some related posts include