Download 1 Lesson 9 Course 3 (student notes) Objective: TSW use factor trees

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Lesson 9
Course 3 (student notes)
Objective: TSW use factor trees to find the prime factorization of counting numbers.
TSW apply tests of divisibility.
PRIME NUMBERS: Counting numbers greater than _____________ and whose only ______________ are the number
itself and ______________-.
Ex. 2, 3, 5, 7, 11 and 13
COMPOSITE NUMBERS: Counting numbers with more than ________________________-.
Ex. 4, 8, 9, 10, and 12
**Counting numbers greater than 1 are either prime or composite.
PRIME FACTORIZATION: A composite number written as the _______________________ of _____________________
numbers.
Example 1.
Find the prime factorization of 36
Two ways to find the prime factorization
Prime Factor Tree
DIVISION BY PRIMES
2
DIVISIBILITY TESTS
If a number is divisible by 2 then the number must be an ______________________ number
Example: 3420 Even number
If a number is divisible by 3 then the ____________________________ is divisible by 3
Example: 3420
; 9 is divisible by 3
If a number is divisible by 5 then the number must _____________ in a ________________________.
Example: 3420 Ends in a zero
A number divisible by 2 and 5 is divisible by ________________________________________
Example: 3420
A number divisible by 2 and 3 is divisible by _________________________________________
Example: 3420
A number is divisible by 9 if the ___________________________________________ is divisible by
_____________________.
Example: 3420
; 9 is divisible by 9
Example 2.
a. 1,237,526
b. 520,611
Determine whether the following numbers are prime or composite. State how you know.