Download Lesson 2 – Prime Factorization

Factors & Multiples
Lesson 1 - Factors & GCF
• I can list factors of a number
• I can find the greatest common factor of two
whole numbers.
Warm Up:
• What is a factor?
Finding Factors
Make a
Factor
A factor rainbow is a way of showing factor pairings.
(two whole numbers whose product is that factor)
What number is each rainbow a factor for?
Greatest Common Factor
Example: Find the GCF of 24 and 36.
Steps:
1) Make a factor rainbow for each number
2) Circle the GREATEST number that they have in
common, that is your GCF.
Find the GCF for each pair of numbers.
20:
36:
15:
60:
72:
56:
Lesson 2 – Prime Factorization
•I can make a factor tree to show prime factorization.
Warm Up
•What is a prime number? Composite?
• Factor Tree Notes
Lesson 3 –Multiples
* I can list the multiples of a whole number.
* I can find the least common multiple of two whole
numbers.
Warm Up
- What is a multiple? (P. 145)
LCM
Example: Find the least common multiple of 6 and 9.
Steps:
1) List the multiples of each number.
Multiples of 6: 6, 12, 18, 24, 30, 36…….
Multiples of 9: 9, 18, 27, 36……………..
2) Circle the smallest number that they have in common.
18, that number is the least common multiple.
Practice!
• LCM & GCF
• Cheat Sheet
– GCF: Factor Rainbow
– Prime Factorization: Factor Tree
– LCM: List multiples