Fractions

Fractions - Sub Topics

  • Fractions
  • Various types of fractions
  • Simplification of Fractions using BODMAS Rule
  • Decimals
  • Solved Questions on Fractions and Decimals
  • Fractions

    Fractions are numeric expressions in the form of p/q, where 'p' and 'q' are whole numbers such that 'q' cannot be zero. 'p' is referred to as the numerator while 'q'  is referred to as the denominator.

    Various types of fractions

    1. Proper Fraction: Proper fractions represent a portion of a whole. They have numerators smaller than their denominators. Even the whole number 0 can be expressed as a proper fraction.
      Examples: 1/2, 1/4, 3/4, 3/7, 5/7, 9/11, 11/13, 17/21, 7/100, 100/101, etc.
    2. Improper Fraction: Improper fractions represent a combination of a whole number and a part of the whole. They have numerators greater than or equal to their denominators. All natural numbers can be expressed as improper fractions.
      Examples: 3/2, 5/4, 9/4, 10/7, 11/7, 12/11, 13/17, 23/21, 101/100, etc.
    3. Mixed Fraction: When an improper fraction is represented as an integer followed by a proper fraction, it is called a mixed fraction. 
      Examples: 5 ? is written as 17/3, 7 ?  is written as 39/5, etc.
    4. Like Fractions: These are fractions with the same denominator but different numerators.
      Examples: 1/3 and 2/3, 3/5 and 4/5, 11/7 and 13/7, 26/15 and 28/15, etc.
    5. Unlike Fractions: Unlike fractions have different denominators.
      Examples: 1/3 and 1/5, 3/5 and 4/7, 11/7 and 13/11, 17/11 and 5/13, etc.
    6. Vulgar fraction: A vulgar fraction is defined as a fraction with a denominator that is a whole number other than 10, 100, 1000, and so on.

    Examples: 3/5, 5/4, 3/4, 11/7, 11/17, 32/11, 23/27, 100/29, 110/ 43, etc. 

    Note: If both the numerator and denominator of a fraction are multiplied by the same nonzero number, the value of the fraction remains unchanged.

    Simplification of Fractions using BODMAS Rule

    When simplifying fractions, the BODMAS rule is a helpful guideline that ensures accurate and systematic simplification. BODMAS stands for Brackets, Orders (exponents and roots), Division and Multiplication (from left to right) and Addition and Subtraction (from left to right).

    Example: Simplify the following expression:
                                         [(3 ½)2 − 2 ?] ÷ 7/6 + 3/46 of 3 ?

    a) −8 ¼
    b) 8 ¼
    c) −8 ¾
    d) 8 ¾

    Answer: d) 8 ¾

    [(3 ½)2 − 2 ?] ÷ 7/6 + 3/46 of 3 ?

    =  [(7/2)2 − 7/3] ÷ 7/6 + 3/46 of 23/6 (Changed to Improper Fractions) 
    =  [49/4 − 7/3] ÷ 7/6 + 3/46 × 23/6 (Changed ‘of’ into multiplication symbol ‘×’ )
    =  [(147 − 28)/12] ÷ 7/6 + 3/46 × 23/6 (Subtraction of two fractions)
    =  [119/12] ÷ 7/6 + 1/4 (Division of two fractions)
    =  [119/12 × 6/7] + 1/4 (Multiplication of two fractions)
    =  17/2 + 1/4 (Addition of two fractions)
    = (34 + 1)/4
    = 35/4
    = 8 ¾ (Changed to Mixed Fractions)

    Decimals

    A decimal number has a whole number followed by a decimal point. Digits following the decimal point have a value less than 1. 

    An example of a decimal number is 418.273. Here, 4 is in the hundreds place, 1 is in the tens place, 8 is in the units place, 2 is in the tenth place, 7 is in the hundredth place and 3 is in the thousandth place.

    The decimal number 418.273 is read as four hundred eighteen point two seven three. All the digits after the decimal point are read one digit at a time.

    cmo-fractions-c7-1

    Example: A piece of cloth is 49.95 metres long. How many pieces can be cut from it if each length is 1.35 metres?

    a) 17 pieces
    b) 27 pieces
    c) 37 pieces
    d) 47 pieces

    Answer: c) 37 pieces

    Explanation: Length of a piece of cloth = 49.95 m
    Length of one piece of cloth cut from it = 1.35 m
    Number of piece = 49.95 ÷ 1.35 = 37 pieces

    Summary & AI Mentor

    Practice Questions on Fractions

    Solved Questions on Fractions

    1. A rope of length 5 ? metres is divided into five equal parts. What is the length of each part so obtained?

    a) 12 metres
    b) 32 metres
    c) 52 metres
    d) 72 metres

    Answer: d) 1.72 metres

    Explanation: Total length of rod =  5 ? metres

    A rod is divided into five equal parts.

    Length of each part = 5 ? metres ÷ 5
    = 43/5 ÷ 5
    = 43/5 × 1/5
    = 43/25
    = 11825 metres
    = (1 + 1825) metres
    = (1 + 18 × 425 × 4) metres [Mutiplied by 4 to get denominator 100, to find decimals.]
    = (1 + 72100) metres
    = (1 + 0.72) metres
    = 1.72 metres

    2. A car runs 54 ¼ km consuming 2 litres of petrol. How much distance will it take to consume 127 litre of petrol?

    a) 34 ? km
    b) 34 ? km
    c) 34 ? km
    d) 34 ? km

    Answer: d) 34 ? km

    Explanation: Distance covered by consuming 2 litres of petrol = 54 ¼ km = 217/4 km

    Distance covered by consuming 1 litre of petrol = 217/4 km ÷ 2
                                                                          = 217/8 km

    Distance covered by consuming 127 litre of petrol = 217/8 km × 127 litre
                                                                             = 217/8 km × 9/7
                                                                              = 279/8 km
                                                                               = 34 ? km

    3. By how much does the sum of 37.786 and 29.576 exceed the sum of 38.789 and 23.548? 

    a) 015
    b) 025
    c) 105
    d) 125

    Answer: b) 5.025

    Explanation: Sum of 37.786 and 29.576 = 67.362

    Sum of 38.789 and 23.548 = 62.337

    Difference (Exceed by) =  67.362 −  62.337 = 5.025

    4. What number should be added to 1323to get 1257?

    a) 20 21
    b) 22 21
    c) − 20 21
    d) − 22 21

    Answer: c) −20 21

    Explanation: To find the number that should be added, subtract 1323 from 1257.

    Required Number = 1257 − 1323

    = 897 − 413
    = 267 − 287 21  [LCM of 7 and 3 = 7 × 3 = 21]
    = − 20 21 or − 2021

    5. When Katrina travelled 35 km by car, she found that ?th of her journey was still left. What was the total distance of the whole journey?

    a) 9313 km
    b) 9323 km
    c) 9318 km
    d) 9338 km

    Answer: a) 9313 km

    Explanation: Katrina travelled 35 km.

    ?th of her journey was still left.

    Fraction of her journey travelled = 1 − 58

    = 8 − 58 [LCM of 1 and 8 is 8.]
    =  38

    38th of the total journey = Her journey travelled

    ⇒ 38 th of the total journey = 35

    ⇒ Total journey = 35 × 83
    ⇒ Total journey = 2803
    ⇒ Total journey = 9313 km

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