Factors and multiples, common factors and common multiples, and Greatest Common Factor (GCF) and Least Common Multiple (LCM) .. these, along with the words that come with them – prime, composite, square, divisible by, etc. – are an integral part of fractions, algebra, and higher math courses such as number theory. This unit introduces all of these concepts in a way that provides meaning for the students and increases retention of these concepts and terminology. It not only addresses fourth an