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    Unit 1:Negative Numbers

    UNIT 2

    FRACTIONS

    B a s i c E s s e n t i a l

    A d d i t i o n a l M a t h e m a t i c s S k i l l s

    Curriculum Development Division

    Ministry of Education Malaysia

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    TABLE OF CONTENTS

    Module Overview 1

    Part A: Addition and Subtraction of Fractions 2

    1.0 Addition and Subtraction of Fractions with the Same Denominator 5

    1.1 Addition of Fractions with the Same Denominators 5

    1.2 Subtraction of Fractions with The Same Denominators 6

    1.3 Addition and Subtraction Involving Whole Numbers and Fractions 7

    1.4 Addition or Subtraction Involving Mixed Numbers and Fractions 9

    2.0 Addition and Subtraction of Fractions with Different Denominator 10

    2.1 Addition and Subtraction of Fractions When the Denominator

    of One Fraction is A Multiple of That of the Other Fraction 11

    2.2 Addition and Subtraction of Fractions When the Denominators

    Are Not Multiple of One Another 13

    2.3 Addition or Subtraction of Mixed Numbers with Different

    Denominators 16

    2.4 Addition or Subtraction of Algebraic Expression with Different

    Denominators 17

    Part B: Multiplication and Division of Fractions 22

    1.0 Multiplication of Fractions 24

    1.1 Multiplication of Simple Fractions 28

    1.2 Multiplication of Fractions with Common Factors 29

    1.3 Multiplication of a Whole Number and a Fraction 29

    1.4 Multiplication of Algebraic Fractions 312.0 Division of Fractions 33

    2.1 Division of Simple Fractions 36

    2.2 Division of Fractions with Common Factors 37

    Answers 42

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    Basic Essential Additional Mathematics Skills (BEAMS) Module

    UNIT 2: Fractions

    1Curriculum Development DivisionMinistry of Education Malaysia

    PART 1

    MODULE OVERVIEW

    1. The aim of this module is to reinforce pupils understanding of the conceptof fractions.

    2. It serves as a guide for teachers in helping pupils to master the basiccomputation skills (addition, subtraction, multiplication and division)

    involving integers and fractions.

    3. This module consists of two parts, and each part consists of learningobjectives which can be taught separately. Teachers may use any parts of the

    module as and when it is required.

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    Basic Essential Additional Mathematics Skills (BEAMS) Module

    UNIT 2: Fractions

    2Curriculum Development DivisionMinistry of Education Malaysia

    PART A:ADDITION AND SUBTRACTION

    OF FRACTIONS

    LEARNING OBJECTIVES

    Upon completion ofPart A, pupils will be able to:

    1. perform computations involving combination of two or more operationson integers and fractions;

    2. pose and solve problems involving integers and fractions;3. add or subtract two algebraic fractions with the same denominators;4. add or subtract two algebraic fractions with one denominator as a

    multiple of the other denominator; and

    5. add or subtract two algebraic fractions with denominators:(i) not having any common factor;(ii) having a common factor.

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    Basic Essential Additional Mathematics Skills (BEAMS) Module

    UNIT 2: Fractions

    3Curriculum Development DivisionMinistry of Education Malaysia

    TEACHING AND LEARNING STRATEGIES

    Pupils have difficulties in adding and subtracting fractions with different

    denominators.

    Strategy:

    Teachers should emphasise that pupils have to find the equivalent form of

    the fractions with common denominators by finding the lowest common

    multiple (LCM) of the denominators.

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    Basic Essential Additional Mathematics Skills (BEAMS) Module

    UNIT 2: Fractions

    4Curriculum Development DivisionMinistry of Education Malaysia

    numerator

    denominator

    Fraction is written in the form of:

    b

    a

    Examples:

    3

    4,

    3

    2

    Proper Fraction Improper Fraction Mixed Numbers

    The numerator is smaller

    than the denominator.

    Examples:

    20

    9,

    3

    2

    The numerator is larger

    than or equal to the denominator.

    Examples:

    12

    108,

    4

    15

    A whole number and

    a fraction combined.

    Examples:

    65

    71 8,2

    Rules for Adding or Subtracting Fractions

    1. When the denominators are the same, add or subtract only the numerators andkeep the denominator the same in the answer.

    2. When the denominators are different, find the equivalent fractions that have thesame denominator.

    Note: Emphasise that mixed numbers and whole numbers must be converted to improper

    fractions before adding or subtracting fractions.

    LESSON NOTES

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    UNIT 2: Fractions

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    1.0 Addition And Subtraction of Fractions with the Same Denominator

    1.1 Addition of Fractions with the Same Denominators

    8

    5

    8

    4

    8

    1i)

    2

    1

    8

    4

    8

    3

    8

    1ii)

    fff

    651

    iii)

    EXAMPLES

    Add only the numerators and keep the

    denominator same.

    Write the fraction in its simplest form.

    Add only the numerators and keep the

    denominator the same.

    Add only the numerators and keep the

    denominator the same.

    8

    1

    8

    4

    8

    5

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    Basic Essential Additional Mathematics Skills (BEAMS) Module

    UNIT 2: Fractions

    6Curriculum Development DivisionMinistry of Education Malaysia

    1.2 Subtraction of Fractions with The Same Denominators

    2

    1

    8

    4

    8

    1

    8

    5i)

    7

    4

    7

    5

    7

    1ii)

    nnn

    213iii)

    Write the fraction in its simplest form.

    Subtract only the numerators and keep

    the denominator the same.

    Subtract only the numerators and keep

    the denominator the same.

    Subtract only the numerators and keep

    the denominator the same.

    8

    5

    8

    1

    2

    1

    8

    4

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    Basic Essential Additional Mathematics Skills (BEAMS) Module

    UNIT 2: Fractions

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    1.3 Addition and Subtraction Involving Whole Numbers and Fractions

    .

    8

    11Calculatei)

    7

    29

    7

    1

    7

    28

    7

    14

    7

    14

    5

    18

    5

    2

    5

    20

    5

    24

    5

    33

    3

    12

    3

    1

    3

    12

    3

    14

    y

    yy

    First, convert the whole number to an improper fraction with thesame denominator as that of the other fraction.

    Then, add or subtract only the numerators and keep the denominatorthe same.

    18

    1

    8

    11

    8

    9

    +

    8

    8

    +

    8

    1

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    Basic Essential Additional Mathematics Skills (BEAMS) Module

    UNIT 2: Fractions

    8Curriculum Development DivisionMinistry of Education Malaysia

    n

    n

    nn

    n

    n

    52

    5252

    k

    k

    k

    k

    kk

    32

    323

    2

    First, convert the whole number to an improper fraction withthe same denominator as that of the other fraction.

    Then, add or subtract only the numerators and keep thedenominator the same.

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    UNIT 2: Fractions

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    1.4 Addition or Subtraction Involving Mixed Numbers and Fractions

    .8

    4

    8

    11Calculatei)

    7

    5

    7

    15

    7

    5

    7

    12

    = 7

    20

    = 7

    6

    2

    9

    4

    9

    29

    9

    4

    9

    23

    = 9

    25

    = 9

    7

    2

    88

    11

    88

    31

    xx

    = 8

    11 x

    First, convert the mixed number to improper fraction. Then, add or subtract only the numerators and keep the

    denominator the same.

    811

    84

    8

    51

    8

    13

    +

    8

    9

    +

    8

    4

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    Basic Essential Additional Mathematics Skills (BEAMS) Module

    UNIT 2: Fractions

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    2.0 Addition and Subtraction of Fractions with Different Denominators

    .2

    1

    8

    1Calculatei)

    To make the denominators the same, multiply both the numerator and the denominator of

    the second fraction by 4:

    Now, the question can be visualized like this:

    ?

    The denominators are not the same.

    See how the slices are different insizes? Before we can add the

    fractions, we need to make them the

    same, because we can't add them

    to ether like this!

    8

    1

    8

    4

    +

    8

    5

    8

    4

    2

    1

    4

    4

    Now, the denominators

    are the same. Therefore,we can add the fractions

    together!

    8

    1

    2

    1

    +

    ?

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    Basic Essential Additional Mathematics Skills (BEAMS) Module

    UNIT 2: Fractions

    11Curriculum Development DivisionMinistry of Education Malaysia

    Hint: Before adding or subtracting fractions with different denominators, we must

    convert each fraction to an equivalent fraction with the same denominator.2.1 Addition and Subtraction of Fractions When the Denominator of One Fraction is

    A Multiple of That of the Other Fraction

    Multiply both the numerator and the denominator with an integer that makes the

    denominators the same.

    (i)6

    5

    3

    1

    6

    5

    6

    2

    6

    7

    =6

    11

    (ii)4

    3

    12

    7

    12

    9

    12

    7

    12

    2

    6

    1

    Change the first fraction to an equivalent

    fraction with denominator 6.

    (Multiply both the numerator and thedenominator of the first fraction by 2):

    6

    2

    3

    1 2

    2

    Add only the numerators and keep the

    denominator the same.

    Change the second fraction to an equivalentfraction with denominator 12.

    (Multiply both the numerator and the

    denominator of the second fraction by 3):

    12

    9

    4

    3 3

    3

    Subtract only the numerators and keep the

    denominator the same.

    Write the fraction in its simplest form.

    Convert the fraction to a mixed number.

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    UNIT 2: Fractions

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    (iii) vv 5

    91

    vv 5

    9

    5

    5

    v5

    14

    Change the first fraction to an equivalent

    fraction with denominator 5v.(Multiply both the numerator and thedenominator of the first fraction by 5):

    vv 5

    51 5

    5

    Add only the numerators and keep the

    denominator the same.

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    UNIT 2: Fractions

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    2.2 Addition and Subtraction of Fractions When the Denominators Are Not Multiple of

    One Another

    Method I

    4

    3

    6

    1

    (i) Find the Least Common Multiple (LCM)

    of the denominators.

    2) 4 , 62) 2 , 3

    3) 1 , 3- , 1

    LCM = 2 2 3 = 12

    The LCM of 4 and 6 is 12.

    (ii) Change each fraction to an equivalent

    fraction using the LCM as thedenominator.

    ( Multiply both the numerator and thedenominator of each fraction by a whole

    number that will make their

    denominators the same as the LCM

    value).

    =

    4

    3

    6

    1

    =12

    9

    12

    2

    =12

    11

    Method II

    4

    3

    6

    1

    (i) Multiply the numerator and thedenominator of the first fraction withthe denominator of the second fraction

    and vice versa.

    =4

    3

    6

    1

    =24

    18

    24

    4

    =24

    22

    =12

    11

    Write the fraction in its

    simplest form.

    This method is preferred but youmust remember to give the

    answer in its simplest form.3

    3

    22

    44 6

    6

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    Basic Essential Additional Mathematics Skills (BEAMS) Module

    UNIT 2: Fractions

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    Multiply the first fraction with the second denominator

    and

    multiply the second fraction with the first denominator.

    1.5

    1

    3

    2

    =5

    5

    3

    2

    +

    3

    3

    5

    1

    15

    3

    15

    10

    =15

    13

    2.8

    3

    6

    5

    =

    8

    8

    6

    5

    6

    6

    8

    3

    =48

    18

    48

    40

    =48

    22

    =24

    11

    Write the fraction in its simplest form.

    EXAMPLES

    Multiply the first fraction by the

    denominator of the second fraction andmultiply the second fraction by the

    denominator of the first fraction.

    Multiply the first fraction by the

    denominator of the second fraction and

    multiply the second fraction by thedenominator of the first fraction.

    Add only the numerators and keep the

    denominator the same.

    Subtract only the numerators and keep

    the denominator the same.

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    UNIT 2: Fractions

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    3.7

    1

    3

    2g

    =3

    3

    7

    7

    7

    1

    3

    2

    g

    =21

    3

    21

    14

    g

    =21

    314 g

    4.53

    2 hg

    3

    3

    55

    5

    3

    2

    hg

    15

    3

    15

    10 hg

    15

    310 hg

    5.dc

    46

    =

    c

    c

    d

    d

    dc

    46

    cd

    c

    cd

    d 46

    =cd

    cd 46

    Multiply the first fraction by thedenominator of the second fraction and

    multiply the second fraction by the

    denominator of the first fraction.

    Write as a single fraction.

    Write as a single fraction.

    Write as a single fraction.

    Multiply the first fraction by the

    denominator of the second fraction and

    multiply the second fraction by thedenominator of the first fraction.

    Multiply the first fraction by thedenominator of the second fraction and

    multiply the second fraction by thedenominator of the first fraction.

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    Basic Essential Additional Mathematics Skills (BEAMS) Module

    UNIT 2: Fractions

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    Convert the mixed numbers to improper fractions.

    Convert the mixed numbers to improper fractions.

    2.3 Addition or Subtraction of Mixed Numbers with Different Denominators

    1.4

    32

    2

    12

    =4

    11

    2

    5

    =4

    11

    2

    5

    2

    2

    =4

    11

    4

    10

    =4

    21

    4

    15

    2.4

    31

    6

    53

    =4

    7

    6

    23

    =6

    6

    4

    4

    4

    7

    6

    23

    =24

    42

    24

    92

    =24

    50

    =12

    25

    =12

    12

    Change the first fraction to an equivalent fraction

    with denominator 4.(Multiply both the numerator and the denominator

    of the first fraction by 2)

    The denominators are not multiples of one another:

    Multiply the first fraction by the denominatorof the second fraction.

    Multiply the second fraction by thedenominator of the first fraction.

    Convert the mixed numbers to improper fractions.

    Convert the mixed numbers to improper fractions.

    Add only the numerators and keep the

    denominator the same.

    Change the fraction back to a mixed number.

    Add only the numerators and keep the

    denominator the same.

    Change the fraction back to a mixed number.

    Write the fraction in its simplest form.

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    Basic Essential Additional Mathematics Skills (BEAMS) Module

    UNIT 2: Fractions

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    The denominators are not multiples of one anotherMultiply the first fraction with the second denominator

    Multiply the second fraction with the first denominator

    The denominators are not multiples of one anotherMultiply the first fraction with the second denominatorMultiply the second fraction with the first denominator

    2.4Addition or Subtraction of Algebraic Expression with Different Denominators

    1.22

    m

    m

    m

    =)2(

    )2(

    2

    2

    22

    m

    mm

    m

    m

    =

    22

    2

    22

    2

    m

    mm

    m

    m

    =)2(2

    )2(2

    m

    mmm

    =)2(2

    222

    m

    mmm

    =)2(2

    2

    m

    m

    2.y

    y

    y

    y 1

    1

    =

    )1(

    )1(1

    1

    y

    y

    y

    y

    y

    y

    y

    y

    =

    )1(

    )1)(1(2

    yy

    yyy

    =)1(

    )1(22

    yy

    yy

    =)1(

    122

    yy

    yy

    =)1(

    1

    yy

    Remember to usebrackets

    Write the above fractions as a singlefraction.

    The denominators are not multiples of one another:

    Multiply the first fraction by the denominatorof the second fraction.

    Multiply the second fraction by thedenominator of the first fraction.

    Expand:

    m (m2) = m22m

    Expand:

    (y1) (y + 1) =y2 +yy12

    =y21

    Expand:

    (y21) =y2 + 1

    Write the fractions as a singlefraction.

    The denominators are not multiples of one another:

    Multiply the first fraction by the denominatorof the second fraction.

    Multiply the second fraction by thedenominator of the first fraction.

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    Basic Essential Additional Mathematics Skills (BEAMS) Module

    UNIT 2: Fractions

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    The denominators are not multiples of one anotherMultiply the first fraction with the second denominator

    Multiply the second fraction with the first denominator

    3.

    24

    5

    8

    3

    n

    n

    n

    =n

    n

    n

    n

    n

    n

    n 8

    8

    24

    4

    4

    5

    8

    3

    2

    2

    =)4(8

    )5(8

    )4(8

    1222

    2

    nn

    nn

    nn

    n

    = )4(8

    )5(812

    2

    2

    nn

    nnn

    =)4(8

    84012

    2

    22

    nn

    nnn

    =)4(8

    404

    2

    2

    nn

    nn

    =

    )8(4

    )10(4

    2

    nn

    nn

    =2

    8

    10

    n

    n

    Factorise and simplify the fraction by canceling

    out the common factors.

    Expand:

    8n (5 + n) =40n8n2

    Subtract the like terms.

    Write as a singlefraction.

    The denominators are not multiples of one another:

    Multiply the first fraction by the denominatorof the second fraction.

    Multiply the second fraction by thedenominator of the first fraction.

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    Basic Essential Additional Mathematics Skills (BEAMS) Module

    UNIT 2: Fractions

    19Curriculum Development DivisionMinistry of Education Malaysia

    Calculate each of the following.

    1. 7

    1

    7

    2

    2.

    12

    5

    12

    11

    3. 14

    1

    7

    2

    4.

    12

    5

    3

    2

    5. 5

    4

    7

    2

    6. 7

    5

    2

    1

    7. 313

    22

    8. 9

    72

    5

    24

    9. ss

    12

    10.

    ww

    511

    TEST YOURSELF A

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    UNIT 2: Fractions

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    11. aa 2

    12

    12. ff 3

    52

    13. ba

    42

    14. qp

    51

    15. nmnm5

    3

    7

    2

    5

    2

    7

    5

    16.

    )2(2

    1p

    p

    17. 5

    3

    2

    32 yxyx

    18. xx

    x 5

    2

    412

    19.

    x

    x

    x

    x 1

    1 20.

    2

    4

    2 x

    x

    x

    x

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    UNIT 2: Fractions

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    21.

    4

    84

    2

    36 yxyx

    22.

    2

    9

    4

    3

    2

    n

    n

    n

    23.

    r

    rr

    15

    25

    5

    2

    24.

    p

    p

    p

    p

    2

    232

    25.

    n

    n

    n

    n

    10

    34

    5

    322

    26.

    n

    n

    mn

    nm 33

    27.

    mn

    nm

    m

    m

    5

    5

    28.

    mn

    mn

    m

    m

    3

    3

    29.

    24

    5

    8

    3

    n

    n

    n 30.

    m

    p

    m

    p 1

    3

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    UNIT 2: Fractions

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    PART B:

    MULTIPLICATION AND DIVISION

    OF FRACTIONS

    LEARNING OBJECTIVES

    Upon completion ofPart B, pupils will be able to:

    1. multiply:

    (i) a whole number by a fraction or mixed number;

    (ii) a fraction by a whole number (include mixed numbers); and

    (iii) a fraction by a fraction.

    2. divide:

    (i) a fraction by a whole number;

    (ii) a fraction by a fraction;

    (iii) a whole number by a fraction; and

    (iv) a mixed number by a mixed number.

    3. solve problems involving combined operations of addition, subtraction,

    multiplication and division of fractions, including the use of brackets.

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    UNIT 2: Fractions

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    TEACHING AND LEARNING STRATEGIES

    Pupils face problems in multiplication and division of fractions.

    Strategy:

    Teacher should emphasise on how to divide fractions correctly. Teacher should

    also highlight the changes in the positive (+) and negative () signs as follows:

    Multiplication Division

    (+) (+) = + (+) (+) = +

    (+) () = (+) () =

    () (+) = () (+) =

    () () = + () () = +

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    Basic Essential Additional Mathematics Skills (BEAMS) Module

    UNIT 2: Fractions

    24Curriculum Development DivisionMinistry of Education Malaysia

    1.0Multiplication of Fractions

    Recall that multiplication is just repeated addition.

    Consider the following:

    32

    First,lets assume this box as 1 whole unit.

    Therefore, the above multiplication 32 can be represented visually as follows:

    This means that 3 units are being repeated twice, or mathematically can be written as:

    6

    3332

    Now, lets calculate 2 x 2. This multiplication can be represented visually as:

    This means that 2 units are being repeated twice, or mathematically can be written as:

    4

    2222

    LESSON NOTES

    3 + 3 = 6

    2 + 2 = 4

    2 groups of 3 units

    2 groups of 2 units

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    UNIT 2: Fractions

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    Now, lets calculate 2 x 1. This multiplication can be represented visually as:

    This means that 1 unit is being repeated twice, or mathematically can be written as:

    21112

    It looks simple when we multiply a whole number by a whole number. What if we

    have a multiplication ofa fraction by a whole number? Can we represent it visually?

    Lets consider .2

    12

    Since represents 1 whole unit, therefore2

    1unit can be represented by the

    following shaded area:

    Then, we can represent visually the multiplication of2

    12 as follows:

    This means that2

    1unit is being repeated twice, or mathematically can be written as:

    1

    2

    2

    2

    1

    2

    1

    2

    12

    1 + 1 = 2

    2

    1+

    2

    1= 1

    2

    2

    2 groups of 1 unit

    2 groups of2

    1unit

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    Lets consider again .22

    1 What does it mean? It means

    2

    1out of 2 units and the

    visualization will be like this:

    Notice that the multiplications2

    12 and 2

    2

    1 will give the same answer, that is, 1.

    How about ?2

    3

    1

    Since represents 1 whole unit, therefore3

    1unit can be represented by the

    following shaded area:

    Then, we can represent visually the multiplication 23

    1 as follows:

    This means that3

    1unit is being repeated twice, or mathematically can be written as:

    3

    2

    3

    1

    3

    12

    3

    1

    3

    1+

    3

    1=

    3

    2

    The shaded area is 3

    1unit.

    2

    1out of 2 units 12

    2

    1

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    Lets consider 23

    1 . What does it mean? It means

    3

    1out of 2 units and the visualization

    will be like this:

    Notice that the multiplications3

    12 and 2

    3

    1 will give the same answer, that is,

    3

    2.

    Consider now themultiplication of a fraction by a fraction, like this:

    21

    31

    This means 3

    1out of

    2

    1units and the visualization will be like this:

    Consider now thismultiplication:

    2

    1

    3

    2

    This means

    3

    2out of

    2

    1units and the visualization will be like this:

    2

    1unit

    3

    1out of 2 units

    3

    22

    3

    1

    3

    1out of

    2

    1units

    6

    1

    2

    1

    3

    1

    2

    1unit

    3

    2out of

    2

    1units

    6

    2

    2

    1

    3

    2

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    What do you notice so far?

    The answer to the above multiplication of a fraction by a fraction can be obtained by

    just multiplying both the numerator together and the denominator together:

    6

    1

    2

    1

    3

    1

    9

    2

    3

    1

    3

    2

    So, what do you think the answer for3

    1

    4

    1 ? Do you get

    12

    1as the answer?

    The steps to multiply a fraction by a fraction can therefore be summarized as follows:

    1.1 Multiplication ofSimple Fractions

    Examples:

    a)35

    6

    7

    3

    5

    2 b)

    35

    6

    5

    3

    7

    2

    c)35

    12

    5

    2

    7

    6 d)

    35

    12

    5

    2

    7

    6

    Steps to Multiply Fractions:

    1) Multiply the numerators together andmultiply the denominators together.

    2) Simplify the fraction (if needed).

    Remember!!!

    (+) (+) = +

    (+) () =

    () (+) =

    () () = +

    Multiply the two numerators together and the two denominators together.

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    1.2 Multiplication of Fractions with Common Factors

    6

    5

    7

    12 or

    6

    5

    7

    12

    1.3 Multiplication of a Whole Number and a Fraction

    6

    152

    =

    6

    31

    1

    2

    =

    6

    31

    1

    2

    =3

    31

    =3

    110

    Second Method:

    (i) Simplify the fraction by cancelingout the common factors.

    6

    5

    7

    12

    (i) Then, multiply the twonumerators together and the twodenominators together, andconvert to a mixed number, if

    needed.

    6

    5

    7

    12

    7

    31

    7

    10

    2

    1

    Convert the mixed number to improper

    fraction.

    Simplify by canceling out the common

    factors.

    Remember

    2 =1

    2

    First Method:

    (ii)Multiply the two numeratorstogether and the twodenominators together:

    6

    5

    7

    12 =

    42

    60

    (ii) Then, simplify.

    7

    31

    7

    10

    42

    60

    10

    7

    3Multiply the two numerators together and

    the two denominators together.

    Remember: (+) () = ()

    Change the fraction back to a mixed number.

    1

    1

    2

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    1. Find10

    15

    12

    5

    Solution:10

    15

    12

    5

    =8

    5

    2. Find5

    2

    6

    21

    Solution :5

    2

    6

    21

    =5

    2

    6

    21

    5

    7

    =5

    21

    Simplify by canceling out the common

    factors.

    Note that3

    21can be further simplified.

    Simplify further by canceling out the

    common factors.

    3

    1

    Simplify by canceling out the common factors.

    EXAMPLES

    Multiply the two numerators together and the

    two denominators together.

    Remember: (+) () = ()

    Multiply the two numerators together and

    the two denominators together.

    Remember: (+) () = ()

    3

    1

    1

    7

    Change the fraction back to a mixed

    number.

    2

    1

    4

    5

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    1.4 Multiplication of Algebraic Fractions

    1. Simplify 4

    52 x

    x

    Solution :4

    52 x

    x

    =2

    5

    =212

    2. Simplify

    m

    n

    n4

    9

    2

    Solution:

    mn

    n4

    9

    2

    =

    1

    4

    2

    9

    2

    mn

    n

    n

    =1

    )2(

    2

    9 mn

    = nm22

    9

    1 2

    1 1Simplify the fraction by canceling out the xs.

    Multiply the two numerators together and

    the two denominators together.

    Simplify the fraction by canceling the

    common factor and the n.

    Multiply the two numerators together

    and the two denominators together.

    Write the fraction in its simplest form.

    Change the fraction back to a mixednumber.

    2

    1

    1

    1

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    1. Calculate 27

    25

    5

    92. Calculate

    20

    14

    7

    3

    12

    45

    3. Calculate

    4

    112 4. Calculate

    5

    14

    3

    1

    5. Simplify

    k

    m3 6. Simplify )5(

    2m

    n

    7. Simplify

    14

    3

    6

    1

    1

    x

    8. Simplify )32(2 dan

    9. Simplify

    yx10

    95

    3

    2 10. Simplify

    x

    x 120

    4

    TEST YOURSELF B1

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    2.0 Division of Fractions

    Consider the following:

    36

    First,lets assume this circle as 1 whole unit.

    Therefore, the above division can be represented visually as follows:

    This means that 6 units are being divided into a group of 3 units, or mathematically

    can be written as:

    236

    The above division can also be interpreted as how many 3s can fit into 6. The answer is

    2 groups of 3 units can fit into 6 units.

    Consider now a division of a fraction by a fraction like this:

    .8

    1

    2

    1

    LESSON NOTES

    How many8

    1is in

    6 units are being divided into a group of 3

    units:

    236

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    This means How many is in ?

    8

    1

    2

    1

    The answer is 4:

    Consider now this division:

    .4

    1

    4

    3

    This means How many is in ?

    4

    1

    4

    3

    The answer is 3:But, how do you

    calculate the answer?

    How many4

    1is in ?

    4

    3

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    Consider again .236

    Actually, the above division can be written as follows:

    3

    16

    3

    636

    Notice that we can write the division in the multiplication form. But here, we have to

    change the second number to its reciprocal.

    Therefore, if we have a division of fraction by a fraction, we can do the same, that is,

    we have to change the second fraction to its reciprocal and then multiply the

    fractions.

    Therefore, in our earlier examples, we can have:

    4

    2

    8

    1

    8

    2

    1

    8

    1

    2

    1(i)

    The reciprocal of a

    fraction is found by

    inverting the

    fraction.

    Change the second fraction to its

    reciprocal and change the sign to .

    The reciprocal

    of8

    1is .

    1

    8

    These operations are the same!

    The reciprocal

    of3 is .3

    1

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    3

    1

    4

    4

    3

    4

    1

    4

    3(ii)

    The steps to divide fractions can therefore be summarized as follows:

    2.1 Division of Simple Fractions

    Example:

    7

    3

    5

    2

    =3

    7

    5

    2

    =15

    14

    Change the second fraction to its reciprocal

    and change the sign to .

    Multiply the two numerators together and

    the two denominators together.

    Steps to Divide Fractions:

    1. Change the second fraction to itsreciprocal and change the sign to .

    2. Multiply the numerators together andmultiply the denominators together.

    3. Simplify the fraction (if needed).

    Tips:

    (+) (+) = +

    (+) () =

    () (+) =

    () () = +

    Change the second fraction to its

    reciprocal and change the sign to .

    The reciprocal

    of4

    1is .

    1

    4

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    2.2 Division of Fractions With Common Factors

    Examples:

    9

    2

    21

    10

    =2

    9

    21

    10

    =2

    9

    21

    10

    =7

    15

    =7

    12

    7

    6

    5

    3

    6

    7

    5

    3

    10

    7

    7

    65

    3

    1

    5 3

    7

    1

    2

    Express the fraction in division form.

    Change the second fraction to its reciprocal and

    change the sign to .

    Simplify by canceling out the common factors.

    Change the fraction back to a mixed number.

    Change the second fraction to its reciprocal

    and change the sign to .

    Then, simplify by canceling out the common

    factors.

    Multiply the two numerators together and the

    two denominators together.

    Remember: (+) () = ()

    Multiply the two numerators together and thetwo denominators together.

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    1. Find6

    25

    12

    35

    Solution :6

    25

    12

    35

    =25

    6

    12

    35

    =

    10

    7

    2. Simplify 4

    52 x

    x

    Solution : xx 5

    42

    = 2

    5

    8

    x

    3. Simplify2

    x

    y

    Solution :

    2x

    y

    2

    1x

    y

    x

    y

    2

    5

    7

    Change the second fraction to its reciprocal

    and change the sign to .Then, simplify by canceling out the common

    factors.

    Method I

    EXAMPLES

    Change the second fraction to its reciprocal

    and change the sign to .

    Multiply the two numerators together and the twodenominators together.

    Express the fraction in division form.

    Change the second fraction to its reciprocal

    and change to .

    Multiply the two numerators together and the two

    denominators together.

    Remember: (+) () = ()

    Multiply the two numerators together and the

    two denominators together.

    2

    1

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    Multiply the numerator and the denominator of

    the given fraction with x

    2

    x

    y

    =

    2x

    y

    x

    x

    =x

    xx

    y

    2

    =

    x

    y

    2

    4. Simplify5

    )1( 1r

    Solution:

    5

    )1( 1r

    =

    5

    )1

    1(r

    r

    r

    =

    r

    r

    5

    1

    The given fraction.

    ris the denominator ofr

    1.

    Multiply the given fraction withr

    r.

    Note that:

    1)1

    1( rrr

    Method II

    The numerator is also

    a fraction with

    denominatorx

    Multiply the numerator and the denominator of the

    given fraction byx.

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    1. Calculate2

    21

    7

    3 2. Calculate165

    87

    95

    3. Simplify3

    48 y

    y

    4. Simplify

    k

    2

    16

    5. Simplify

    3

    5

    2

    x 6. Simplify

    n

    m

    n

    m

    3

    242

    7. Simplify8

    1

    4

    y

    8. Simplify

    x

    x

    11

    TEST YOURSELF B2

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    9. Calculate5

    )1(341

    10. Simplifyy

    x15

    11. Simplify

    3

    2

    9

    41 x

    12. Simplify

    15

    1

    1

    p

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    TEST YOURSELF A:

    1.7

    3

    2.

    2

    1

    3.

    14

    5

    4.4

    1

    5.

    35

    38or

    35

    31

    6.

    14

    3

    7.13

    67or

    13

    25

    8.45

    73or

    45

    281

    9.s

    3

    10.w

    6

    11.

    a2

    5

    12.

    f3

    1

    13.ab

    ab 42

    14.

    pq

    pq 5

    15. nm

    16.2

    33 p

    17.10

    1716 yx

    18.x

    x 12

    19.)1(

    1

    xx

    20. 2 21.2

    8 yx

    22.2

    9

    47

    n

    n

    23.

    r

    r

    3

    12

    24.2

    2

    2

    6

    p

    p

    25.2

    2

    10

    647

    n

    nn

    26.m

    m1

    27.

    n

    n

    5

    5

    28.n

    n

    3

    3

    29.

    28

    10

    n

    n

    30.

    m

    p

    3

    34

    ANSWERS

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    UNIT 2: Fractions

    TEST YOURSELF B1:

    1.3

    21

    3

    5or 2.

    8

    11

    8

    9 or 3.

    2

    15

    2

    11or

    4.5

    21

    5

    7 or 5.

    k

    m36.

    2

    5mn

    7.4

    x8. ndna

    2

    3 9. yx

    5

    3

    3

    10

    10.

    4

    15 x

    TEST YOURSELF B2:

    1.49

    22.

    9

    51

    9

    14 or 3.

    2

    6

    y

    4. 8k5.

    x5

    66.

    m

    6

    7.)1(2

    1

    y 8.

    1

    2

    x

    x

    9.20

    9

    10.xy

    x 15 11.

    6

    13x 12.

    p4

    5