1. 1.2 Fractions 1. Write equivalent fractions.
2. Write equivalent fractions with the LCD.
3. Write the prime factorization of a number.
4. Simplify a fraction to lowest terms.
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2. Fractions
 Numerator
 Denominator
 Part
 Whole

3. Equivalent Fractions
∙ 2
∙ 2
∙ 3
∙ 3
÷ 3
∙ 2
÷ 3
∙ 2

4. Factors:
Expressions that are being multiplied.
Prime number:
A natural number that has only 1 and the number itself as factors.
2, 3, 5, 7, 11, 13, 17, 19, 23,…
Prime factorization:
A factorization that contains only prime factors.
1, 2, 3, 4, 6 and 12 are factors of 12.
Prime factorization of 12 is 2 ∙ 2 ∙ 3.

5. Find the prime factorization of 20.
Factor Tree
Factor Tower
Divide by prime numbers!
2, 3, 5, 7, 11, …

6. 0, 2, 4, 6, 8
259:
= 16
372:
= 12
5, 10, 15, 20, …
10, 20, 30, 40, …

7. Find the prime factorization of 60.
Factor Tree
Factor Tower

8. Find the prime factorization of 48.
Factor Tree
Factor Tower

9. Find the LCD.
Using Multiples 6:
6, 12, 18, 24, 30, 36, 42, 48, 54, 60
10:
10, 20, 30, 40, 50, 60
LCD = 30
Use when numbers are small.

10. Using Prime Factorization
Find the LCD.
Using Prime Factorization
2∙3
2∙5
2 ∙ 3
∙ 5
= 30
LCD:

11. Find the LCD.
Using Multiples
12:
12, 24, 36, 48, 60 9:
9, 18, 27, 36
LCD = 36

12. Using Prime Factorization
Find the LCD.
Using Prime Factorization
2∙2∙3
3∙3
LCD:
2∙2∙3
∙ 3
= 36

13. Write the fractions as equivalent fractions with the LCD.24 ∙3 ∙2

14. Write the fractions as equivalent fractions with the LCD.
Suggestion:
2∙2∙2∙2
2∙2∙3∙3
LCD:
2∙2∙2∙2∙3∙3
= 144 ∙9 ∙4

15. Reduce Fractions. GCF: 3 Using Prime Factorization
Using Greatest Common Factor
GCF: 3 3 4

16. Reduce Fractions. GCF: 6 Using Greatest Common Factor 5 7
Using Prime Factorization

17. Reduce Fractions. GCF: ? Common Factor: 10 Common Factor: 2
Using Greatest Common Factor
Common Factor: 10
Common Factor: 2 11
119
Using Prime Factorization

18. Answer 3 out of 14 employees have optional eye insurance.
At a company, 225 of the 1050 employees have optional eye insurance coverage as part of their benefits package. What fraction of the employees have optional eye insurance coverage?
÷ 5
÷ 5
÷ 3
Answer 3 out of 14 employees have optional eye insurance.