04 Pri WB Math P5.pdf

8/14/2019 04 Pri WB Math P5.pdf

1/8

Mathematics Pratomsuksa 5 Chapter 4 Notes

26

Equivalent fractionsEquivalent fractions are fractions of the same value.

Example:

13

= 26

= 39

To nd the equivalent fractions of a fraction, multiply or divide both thenumerator and the denominator of the fraction by the some number.

Example: 23

= 46

= 812

;

2 2

2 2

3648 = 9

12 = 3

4

4 3

4 3

Comparing fractions

Example:

13

23

smallernumerator

samedenominator

greaternumerator

,

Example: 13

14

smallerdenominator

samenumerator

greaterdenominator

.

4 F r a c t i o n s

04 Pri Edu WB Math P5.indd 26 2/17/11 9:33:19 AM


2/8


27

Example:

34

58

differentdenominators

differentnumerators

68

.

58

greaternumerator

denominatorsequalized

smallernumerator

Simplest forms of fractions

1. The simplest form of a fraction is its equivalent fraction with anumerator and a denominator that are not commonly divisible byany whole number other than 1.

47

, 12

, 1317

and 521

are examples of simplest forms of fractions.

Fractions equivalent to whole numbers

1. A fraction that has the same numerator and denominator isequivalent to 1.

22

= 33

= 1212

= 1515

= 1

2. Fractions with numerators that are divisible by their denominators areequivalent to whole numbers.

42

= 2, 93

= 3, 164

= 4, 105

= 2, 3010

= 3



3/8


28

Proper fractions and improper fractions 1. Proper fractions have numerators that are smaller than their

denominators.

23

, 45

, 79

, and 1013

are examples of proper fractions.

2. Improper fractions have numerators that are equal to or greaterthan their denominators.

42

, 33

, 75

, and 116

are examples of improper fractions.

Mixed numbers 1. Mixed numbers consist of whole numbers and proper fractions.

1 12

, 5 35

and 10 710

are examples of mixed numbers.

2. To convert a mixed number to an improper fraction, multiply thewhole number by the denominator and add the product to thenumerator. Maintain the denominator.

Example: 2 35

= (2 5) + 35

10 + 3 = 5 13 = 5

3. To convert an improper fraction to a mixed number, divide thenumerator by the denominator. Then, write the quotient as thewhole number, the remainder as the numerator and the divisor asthe denominator of the mixed number.

Example: 13 = 13 8 8

= 1 58

18 13 8 5

denominator

whole number

numerator



4/8

Mathematics Pratomsuksa 5 Chapter 4 Exercises

29

A Fill in the correct numbers to show the equivalentfractions.

1. 2.

24

=1

2

23

= 46

3. 4.

6

8 =34

45

= 810

B Fill in the correct numbers in the blanks.

1.3 60 =

4 80

2. 1 7 = 6 42

3. 7 70 = 12 120

4. 12 4 = 18 6

5. 8 2 = 20 5

6. 70 7 = 100 10

7.3 9 27 = =

5 15 45

8.4 20 40 = =

7 35 70



5/8

Mathematics Pratomsuksa 5 Chapter 4 Exercises

30

C Fill in the symbol > or < in the boxes.

1. 37

39

> 2. 18

58

5. 231

235

> 6. 442

842

Documents

04 Pri WB Math P5.pdf