Copyright 2014 Scott Storla Rational Numbers. Copyright 2014 Scott Storla Vocabulary Rational number...

Preview:

Citation preview

Copyright 2014 Scott Storla

Rational Numbers

Copyright 2014 Scott Storla

Vocabulary

Rational number

Proper fraction

Improper fraction

Mixed number

Prime number

Composite number

Prime factorization

Reciprocal

Copyright 2014 Scott Storla

The Rational Numbers

Copyright 2014 Scott Storla

Copyright 2014 Scott Storla

Irrational NumbersThe real numbers which are not rational.

3 14159265358979. ...

22

73 14158. ...

355

1133 1415929. ...

104348

332153 1415926539. ...

Trying to find a rational number that’s equal to pi.

Copyright 2014 Scott Storla

Fractions

Copyright 2014 Scott Storla

Proper Fraction

In a proper fraction the numerator (top) is less than the denominator (bottom).

2

3

The value of a proper fraction will always be between 0 (inclusive) and 1 (exclusive).

Copyright 2014 Scott Storla

Improper Fraction

In an improper fraction the numerator (top) is greater than or equal to the denominator (bottom).

3

2

The value of an improper fraction is greater than or equal to 1.

Copyright 2014 Scott Storla

Prime Factorization

Copyright 2014 Scott Storla

Prime Number

A natural number,

greater than 1,

which has unique natural number factors 1 and itself.

Ex: 2, 3, 5, 7, 11, 13

Copyright 2014 Scott Storla

Composite Number

A natural number,

greater than 1,

which is not prime.

Ex: 4, 6, 8, 9, 10

Copyright 2014 Scott Storla

Prime Factorization

I have prime factored a composite number when

the number is written as the product of prime factors.

We say 2 2 3 is the prime factorization of 12

since the factors 2 and 3 are prime.

We don't consider 2 6 a prime factorization of 12

because 6 is not prime.

Copyright 2014 Scott Storla

Prime Factorization

To write a natural number as the product of prime factors.

Ex: 12 = 2 x 2 x 3

Copyright 2014 Scott Storla

Factor Rules

Copyright 2014 Scott Storla

Decide if 2, 3, and/or 5 is a factor of

42

310

987

4950

Copyright 2014 Scott Storla

List all positive integers between 51 and 61 inclusive.

List all prime numbers between 51 and 61 inclusive.

List all rational numbers with denominators of 1 between 110 and 120 inclusive.

List all prime numbers between 110 and 120 inclusive.

List all natural numbers between 31 and 40 inclusive.

List all prime numbers between 31 and 40 inclusive.

Copyright 2014 Scott Storla

Building a factor tree for 20

The prime factorization of 20 is 2 x 2 x 5.

20

45

22

Copyright 2014 Scott Storla

Property – The Commutative Property of Multiplication

English: The order of the factors doesn’t affect the product.

Example: 2 4 4 2

Note: Division is not commutative. For instance 4 2 2 4 .

5 2 3 2 2 2 3 5

Copyright 2014 Scott Storla

The Fundamental Theorem of Arithmetic

Every natural number, greater than 1, has a unique prime factorization.

Example: 20 5 4 2 10 2 2 5

Copyright 2014 Scott Storla

Procedure – To Prime Factor a Natural Number

1. Build a factor tree using the factor rules for 2,3,and 5.

2. After step 1 divide uncircled factors by the prime numbers beginning with 7 up to the square root of the number.

3. Write your prime factors in order from smallest to largest.

Copyright 2014 Scott Storla

The prime factorization of 24 is 2 x 2 x 2 x 3.

24

2 12

Find the prime factorization of 24

2 6

2 3

Copyright 2014 Scott Storla

The prime factorization of 315 is 3 x 3 x 5 x 7.

315

5 63

Find the prime factorization of 315

3 21

7 3

Copyright 2014 Scott Storla

The prime factorization of 119 is 7 x 17.

119

7 17

Find the prime factorization of 119

Copyright 2014 Scott Storla

The prime factorization of 495 is 3 x 3 x 5 x 11.

495

5 99

Find the prime factorization of 495

9 11

3 3

Copyright 2014 Scott Storla

Prime Factorization

Copyright 2014 Scott Storla

Reducing Fractions

Copyright 2014 Scott Storla

Property – The Associative Property of Multiplication

English: The grouping of the factors doesn’t affect the product.

Example: 2 3 4 2 3 4

Note: Division is not associative. For instance 8 4 2 8 4 2 .

Property – The Multiplicative Identity

English: 1 is the multiplicative identity. Multiplying an expression by

one results in an equivalent expression.

Example:

3 31

4 4

Copyright 2014 Scott Storla

Reducing Fractions

A fraction is reduced when the numerator and denominator have no common factors other than 1.

6

10

2 3

2 5

3

15

3

5

32

2 5

5

2

2

3

Copyright 2014 Scott Storla

Reducing Fractions

A fraction is reduced when the numerator and denominator have no common factors other than 1.

6

10

2 3

2 5

3

5

6

12

2 3

2 2 3

1

1

2

2 3

2 5 3

15

1

Copyright 2014 Scott Storla

Procedure – Reducing Fractions

1. Prime factor the numerator and denominator.

2. Reduce common factors.

3. Find the product of the factors in the numerator and the product of the factors in the denominator.

No “Gozinta” method allowed

Copyright 2014 Scott Storla

No “Gozinta” (Goes into) method allowed

84

210

42

105

14

35

2

5

2

5

Copyright 2014 Scott Storla

No “Gozinta” (Goes into) method allowed

2

2

2

3 2

x x

x x

1x

1x

Copyright 2014 Scott Storla

Simplify using prime factorization

18 2 3 3

24 2 2 2 3

2 3 3

2 3 2 2

31 1

2 2

3

4

18

24

2 3 3

2 2 2 3

3

4

Copyright 2014 Scott Storla

18

24

2 3 3

2 2 2 3

3

4

Simplify using prime factorization

Copyright 2014 Scott Storla

90

63

2 3 3 5

3 3 7

10

7

Simplify using prime factorization

Copyright 2014 Scott Storla

120

45 2 2 2 3 5

3 3 5

8

3

Reduce using prime factorization

Copyright 2014 Scott Storla

126

234

2 3 3 7

2 3 3 13

7

13

Reduce using prime factorization

Copyright 2014 Scott Storla

168

315

2 2 2 3 7

3 3 5 7

8

15

Reduce using prime factorization

Copyright 2014 Scott Storla

Reducing Fractions

Copyright 2014 Scott Storla

Multiplying Fractions

Copyright 2014 Scott Storla

using prime factorizationMultiply

51 1 1

14

2

2

6 25

15 28

5

14

3 5

5 5 2 32 2 7

3

3

5

5 5

2 7

6 25

15 28 150

420

Copyright 2014 Scott Storla

Procedure – Multiplying Fractions

1. Combine all the numerators, in prime factored form, in a single numerator.

2. Combine all the denominators, in prime factored form, in a single denominator.

3. Reduce common factors

4. Multiply the remaining factors in the numerator together and the remaining factors in the denominator together.

Copyright 2014 Scott Storla

6 25

15 28

2 3 5 5

3 5 2 2 7

5

14

Multiply using prime factorization

Copyright 2014 Scott Storla

5 5

253 3

3 5 15 69 25

Multiply using prime factorization

2 3

Copyright 2014 Scott Storla

3 7 2 2 7 2 3 5 18 5 7

21 28 30 2 3 3 5 7 1

28

Multiply using prime factorization

Copyright 2014 Scott Storla

1 3 2 3 5 1 7 5

2 7 7 2 3

3 30 35

2 49 6

75

14

Multiply using prime factorization

3 30 55

2 49 6

5514

Copyright 2014 Scott Storla

Dividing Fractions

Copyright 2014 Scott Storla

Reciprocal

The reciprocal of a number is a second number which when multiplied to the first gives a product of 1.

The reciprocal of is because

7 11

1 7

3 21

2 3

3

2 2

3

The reciprocal of is because 7 1

7

Copyright 2014 Scott Storla

3

10

10

3

10

310

3

1

Procedure – Dividing Fractions

1. To divide two fractions multiply the fraction in the numerator by the reciprocal of the fraction in the denominator.

6

53

10

2 3 2 5

5 3

6 105 3

1

6

5

10

3 4

Copyright 2014 Scott Storla

Procedure – Dividing Fractions

1. To divide two fractions multiply the fraction in the numerator by the reciprocal of the fraction in the denominator.

6

53

10

6 10

5 3

2 3 2 55 3

4

Copyright 2014 Scott Storla

10181524

2 5 1 2 2 2 3

2 3 3 3 5

8

9

Divide using prime factorization

10 24

18 15

Copyright 2014 Scott Storla

355014

7 5

2 5 5 2 7

1

20

Divide using prime factorization

35 1

50 14

14

1

Copyright 2014 Scott Storla

1216

9

1 2 2 2 2 3 3

2 2 3

12

Divide using prime factorization

16 9

1 12

1

16

Copyright 2014 Scott Storla

59

143

21

15 7 3

3 3 2 7

1

6

Divide using prime factorization

5 3 73 3 3 5

143

79

143

7 3

9 14

6115

Copyright 2014 Scott Storla

Dividing Fractions

Recommended