The factors of a number are integers that can be divided evenly (without a remainder) into the number. For example, the number 20 is divisible by 5 in that 5 can go into 20 four times without going over or under the number 20. However, the number 20 is not divisible by 6, as 6 can only go into the number 20 three times before going over.
Common factors are factors that two or more numbers have in common, such as 4 is a common factor of 16 and 20. The greatest common factor of two or more numbers is the largest common factor shared between numbers, such as 7 is the greatest common factor of 14 and 21.
Prime factors are the factors of a number that are prime numbers. 1 is NOT a prime factor.
The multiples of a given number are those numbers that can be divided by that given number without a remainder. You can find the multiples of a number by multiplying it by another number, such as 2 1 2 and 2 2 4. Thus, 2 and 4 are multiples of 2. Incidentally, if the sum of the digits of a number is divisible by 3, then the number is a multiple of 3 (ex. 561→5 6 1 12). Any number that is a multiple of all the given numbers is called a common multiple. The least common multiple is the smallest multiple of two or more numbers, such as 24 is the least common multiple of 8 and 12.
Shelby Joe 周 is the Founder of Piqosity. He has more than 20 years of experience in education as an entrepreneur, professor, and tutor. Shelby earned his BA in Political Science from Rice University. Born and raised in Mississippi, he now resides in Houston but has also lived in Beijing, Shanghai, and Hamburg.