I know it sounds really easy but I was just wondering whether there is a quicker way to work out the lowest common multiple of a pair of numbers without having to write down all the multiples and picking out the ones in common.
If you write a number as a number of its prime factors, all you need to do is draw a venn diagram, then put all the factors from your first number into the first circle and the second lot of factors into the second circle, then put any numbers which are common for both your starting numbers in the middle. Much like a venn diagram
Then you just multiply all the numbers together from both circles and the middle section and theres your lowest common multiple.
I know it sounds complicated but its really not, and its the easiest way to do it.