GCD (Greatest Common Divisor)

The Greatest Common Divisor (GCD) is the largest number that divides two or more numbers exactly, with no remainder. For example, the GCD of 8 and 12 is 4, because 4 is the biggest number they both share as a divisor. It helps in simplifying fractions, finding common factors, and solving problems involving divisibility. Think of it as discovering the biggest "building block" they have in common, which can be used to break down numbers into simpler parts. The GCD is a fundamental concept in number theory and mathematical problem-solving.