GCF and LCM

Find the GCF and the LCM of a set of numbers with this calculator which also shows the steps. The Greatest Common Factor (GCF) is the greatest factor that is common to two or more numbers (they share it); the Least Common Multiple (LCM) of two (or more) numbers is the smallest number (excluding zero) that is a multiple of both of the numbers.
It is also intended to be a teaching tool.