1. HCF & LCM

The Highest Common Factor (HCF) is the largest number that divides into two or more numbers evenly. Think of it as the biggest shared piece you can cut from different lengths of rope. The Least Common Multiple (LCM) is the smallest number that is a multiple of two or more numbers. This is useful for finding when events will happen at the same time, like friends meeting on a jogging track. The product of two numbers is equal to the product of their HCF and LCM.