1. 3.1 Factors and Multiples of Whole Numbers (Outcome FP10.1)

2. Definitions Prime Number: Factor: Prime Factor:
Any number that is only divisible by 1 and itself.
Factor:
A number that divides another number.
“6 is a factor of 24”
Prime Factor:
Any factor that has only two divisors, 1 and itself.
“2 is a prime factor of 4”

3. Targets of this Lesson
To learn how to determine the greatest common factors or least common multiples.
To explain the relationship between factors and multiples.
To determine the prime factors of a whole number and explain the strategies used.

4. Prime Factorization
A number that is written as a product of its prime factors.
There are two main methods of Prime Factorization:
A Factor Tree
Repeated Division

5. Tree Factoring
3300

6. Repeated Division
3300

7. Greatest Common Factor
The greatest factor two or more numbers have in common.
There are two methods for finding the GFC:
List and Compare Factors
Write the Prime Factorization of all numbers (multiply everything in common)

8. List and Compare Factors
138
198

9. Write Prime Factors of Both Numbers
138
198

10. Least Common Multiple
The lowest number that is divisible by two or more numbers.
There are two steps for determining the LCM:
Write the Prime Factorization of all numbers
Take the largest POWER of each PRIME FACTOR and MULTIPLY them together.

11. List Multiples 18 20 30

12. Textbook Page
Questions:
3 (a,b,c)
4 (d,e,f)
5 (all)
6 (a,b)
8 (b,e,f)
9 (a)
10 (a,b,c)
11 (d) 12 17