Students first use the familiar prime factorization method to calculate the GCD and LCM of two numbers. Second, they apply Euclid’s algorithm, an iterative process for finding the GCD, in conjunction with a formula for the LCM given the GCD. In order to use the algorithm, they must first grasp the remainder operation, which they explore via a table of values. Lastly, they check their answers with the calculator’s GCD and LCM functions.