Greatest Common Factor and Least Common Multiples GCF
- Slides: 15
Greatest Common Factor and Least Common Multiples GCF and LCM
What is the difference between a factor and a multiple?
Give me an example of a factor of 15
Give me an example of a multiple of 15
How would you find the GCF of 60 and 96?
There actually 2 ways. You can use prime factorization, or write out all the prime factors for each number.
List the factors of 60: 1, 2, 3, 4, 5, 6, 10, 12, 15, 20, 30, 60 List the factors of 96 1, 2, 3, 4, 6, 8, 12, 16, 24, 32, 48, 96 find the largest factor - 12
…or do prime factorization. Circle all the primes the 2 numbers have in common and multiply one set of them to get your GCF. 96 60 2 30 24 2 15 2 48 2 12 2 3 5 6 2 2 x 3 = 12 2 3
Find the GCF (HCF) of 36, 24, 144 and 96
96 24 36 48 2 2 18 2 12 24 2 9 2 6 2 12 2 3 3 144 4 2 2 12 12 3 6 2 3 2 4 2 2 x 3 = 12 2 3
There are 2 ways to find the LCM as well. You can list the multiples of the numbers or do prime factorization. Find the LCM of 12 and 18
Multiples of 12 are… 12, 24, 36, 48, 60, 72, …. Multiples of 18 are… 18, 36, 54, 72, 90, 108, … The smallest multiple the 2 numbers have in common is the least common multiple.
…or do prime factorization. Write down the number they have in common only once, then write down the leftover numbers. Multiply them all together. 12 18 4 3 2 9 2 2 3 3 Numbers in common are 2 and 3 Leftover numbers are 2 and 3 2 x 3 x 2 x 3 = 36
Find the LCM of 35, 420 and 245
35 42 10 5 245 420 5 49 7 2 5 6 3 7 7 2 Numbers they have in common: 5 and 7 Leftover numbers: 2, 3, 2, 7 Multiply them all together: 5 x 7 x 2 x 3 x 2 x 7 = 2940 7
- Greatest common factor of 18 and 27
- The gcf of 12 and 18
- Factoring greatest common factor
- What is factored form
- Gcf of 48 56 and 72
- Highest common factors and lowest common multiples
- Multiples of 9 and 21
- Gcf of 21 and 49
- Factors of 56 that are perfect squares
- The gcf of two whole numbers is the
- What is the prime factorization of 72
- What is the greatest common factor of 42 and 84
- Common factors of 27 and 45
- Greatest common factor of 48 and 64
- 54 and 24 gcf
- Greatest common factor of 7 and 9