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Factors & Multiples:
Factor: numbers that multiply together to make another number ex: 3 and 4 are factors of 12, there is always a finite set of numbers
Multiples: the result of multiplying a number and an integer
ex: the complete set of multiples of 3 is 3, 6, 9, 12, 15, 18,...
The set of multiples of any number is always an infinite set of numbers.
Multiples are used in facts such as skip counting.
Prime Number: a number is has exactly two factors: 1 and itself
ex: 3 & 7
Composite Numbers: A composite number is a number that has three or more factors
ex: 4 - 1, 2, 4 & 15 - 1, 3, 5, 15
Factor Tree: diagram where you find the factors of a number, then the factors of those numbers, etc. until you can't factor any more.
48
8 6
4 2 3 2
2 2
Greatest Common Factor (GCF): After finding the factors of two or more numbers, you will notice that some are the same or "common," the largest of these numbers is the Greatest Common Factor.
example: factors of 12: 1, 2, 3, 4, 6, 12
factors of 16: 1, 2, 4, 8, 16
The greatest common factor of 12 and 16 is 4.
Least Common Multiple (LCM): the smallest positive number that is a multiple of two or more numbers.
example: Multiples of 3: 3, 6, 9, 12, 15, 18, 21...
Multiples of 5: 5, 10, 15, 20, 25...
The lowest common multiple of 3 and 5 is 15
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