Fractions

Fractions Vocabulary Review

• fraction:

• improper fraction:

• mixed fraction:

Prime Factorization

• breaking down a number into a product of its prime factors

• Example: 400

Greatest Common Factor

• find the prime factorization

• multiply the prime common factors

• Example: 160 80

Least Common Multiple

• find the prime factorization

• find the GCF

• multiply the GCF by the leftover factors

• Example: 96 116

Least Common Denominator

• uses the least common multiple of the denominators

• Example:

• What is the LCD for:16

15,

24

11,

12

5

Ordering Fractions

• can do this two ways:

• order by getting a common denominator, then compare numerators

• order by converting to decimals

• BE SURE: to read the question carefully, so you’re ordering from least to greatest, or greatest to least!!!

Examples

• Order the fractions from greatest to least:

11

14,5

7,

8

11,7

9

Examples

• If a > b, and a and b are positive integers, then which expression is greatest:

baa

1,1,

Adding/Subtracting Fractions

• must have common denominators• adding mixed numbers:

– add fractions first– add whole numbers– reduce the fraction, if needed

• subtracting mixed numbers:– subtract fractions first, borrowing if needed– subtract whole numbers– reduce the fraction, if needed

Examples

• Find the sum or difference:

9

52

9

73

10

34

2

16

Examples

• Find the sum or difference:

4

32

5

19

Multiplying/Dividing Fractions

• multiplying fractions:– multiply numerators– multiply denominators– reduce, if needed

• dividing fractions:– flip the second fraction– multiply the fractions– reduce, if needed

• mixed numbers:– change into improper fractions

Examples

• Find the product or quotient:

7

6

3

2

4

3

12

5

Homework

• Orange Book:

• p. 31: 1-6

• p. 36: 1-8

• Purple Book:

• p. 19-20: 1-19