Warm - Up Review Notes… What is a Factor? Describe how you would list the factors of a number?

Greatest Common Factor Topic Greatest Common Factor GCF

Tonight’s Homework (8/29) Find the greatest common factor of the numbers. Using PRIME FACTORIZATION or THE FIGURE FOUR. 99 and 165 132 and 198 88 and 165 168 and 450

Essential Question How would you explain the process of finding the greatest common factor (GCF) of two or more numbers?

Key Terms Common Factor Greatest Common Factor (GCF) Factor Tree Factor Rainbow Figure Four

Common Factor A whole number that is a factor of two or more numbers

Greatest Common Factor (GCF) The Greatest of the Common Factors Another name for Greatest Common Factor is… Greatest Common Divisor (GCD) - This is used when working with fractions

Factor Tree A diagram that can be used to write the prime factorization of a number.

Factor Rainbow A visual used to list the factors of a number in numerical order.

Figure Four A method, using division, used to help find the Greatest common factor between two numbers

Example 1 Write the Factors of 28, 42, and 70 28: 70:

Example 1 Write the Factors of 28, 42, and 70 28: 1, 2, 4, 7, 14, 28 42: 1, 2, 3, 6, 7, 14, 21, 42 70: 1, 2, 5, 7, 10, 14, 35, 70

Example 1 Write the Factors of 28, 42, and 70 28: 1, 2, 4, 7, 14, 28 42: 1, 2, 3, 6, 7, 14, 21, 42 70: 1, 2, 5, 7, 10, 14, 35, 70

Guided Practice Find the GCF… 16, 28 14, 91

Using the GCF to Solve Problems (see pg. 10) (pg. 13 – number 44)

Using Prime Factorization to Find the GCF Find the Prime Factors of 90 & 150 Use a factor tree to solve