Presentation on theme: "Write this in your INTERACTIVE Notebook's table of contents!"— Presentation transcript:
1Write this in your INTERACTIVE Notebook's table of contents! LCM & GCF NotesWrite this in your INTERACTIVE Notebook's table of contents!
2In order to understand the concepts of Greatest Common Factor (GCF) and Least Common Multiple (LCM), we need to define two key terms:Multiple and Factor
3Multiple: Multiples of a number are the result of multiplying that number by some other whole number.
4Factor: Factors are the numbers you multiply to get another number.For example:the factors of 21 are 3 and 7 because 3 x 7 = 21.Factor: A factor of a number will also divide that number evenly, with no remainder.3 is a factor of 15 because 15 ¸ 3 = 5exactly (with no remainder)
5Greatest Common Factor The Greatest Common Factor (GCF) of two or more numbers is the product of all the factors they share in common.In order to find the factors they share in common, we use something called prime factorization to find the number’s factors.We can find a number’s factors 2 different ways.1) Factor tree2) U table
6Circle your prime factors (in this example 2, 2, and 3). Factor TreePrime factorization (or finding primes factors) can be done using a factor tree.Circle your prime factors (in this example 2, 2, and 3).The prime factorization of 12 = or 12 =Remember a means MULTIPLY!2
7Factors come in a pair of 2 numbers. Example: 1 x 2 = 2 2 x 2 = 4 U tableFactors come in a pair of 2 numbers.Example: 1 x 2 = 22 x 2 = 43 x 2 = 6To make sure we do not miss any factor pairs we shoulduse a U table when solving for GCF problems.Whatever # we aresolving for goes on the topList the factors starting with 1List the factor paired with 1Once the last two numbers in your tableMeet you know you have found all the factors.
8Prime NumbersPrime #: is a natural number greater than 1 that has no positive divisors other than 1 and itself.In other words… a prime number is any number whose only factors are 1 and itself.Example: 2, 3, 5, 7, 11, 13, 17…
9Composite NumbersComposite #: a positive integer that has a positive divisor other than one or itself.In other words a composite number is any positive integer greater than one that is not a prime number.