Numbers can be multiplied to get a product. These numbers are called factors of the product.
Multiples of a number are obtained by multiplying the number by natural numbers.
Highest Common Factor or HCF of two numbers is the largest number which is a common factor for these numbers.
Least Common Multiple or LCM of two numbers is the smallest number which is a common multiple for these numbers.
SmartTest on Multiples and Factors
SmartTest on HCF
SmartTest on LCM