Prime Factorization Section 2.5

Objectives Find the prime factorization of a counting number by repeated division Find the prime factorization of a counting method using the tree method

Objective 1: Find the prime factorization of a counting number by repeated division

Obj. 1: Repeated Division The basic elements of all numbers are the prime numbers Every counting number (except 1) is a prime or a combination of prime factors

Obj. 1: Repeated Division To find the prime factorization of a counting number –Divide the counting number and each following quotient by a prime number until the quotient is 1. –Begin with 2 and divide until quotient is odd –Divide by 3 until quotient is not a multiple of 3 –Continue with 5, 7, and so on –Write answer as factors multiplied together –Can use exponents as shorthand

Objectives2: Find the prime factorization of a counting method using the tree method

Obj. 2: Tree Method To find the prime factorization using the tree method –Draw “factor branches” from the given number with any two factors –Draw additional branches from the factor at the end of the branch –Factoring is complete when numbers at end of each branch is a prime number –Write answer as factors multiplied together –Can use exponents as shorthand