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74 Maths

3. Arrange the following unlike fractions in the descending order.

1 1 7 2 4 3 1 9 3 7 5 7 3 5 1 7
(i) , , , (ii) , , , (iii) , , , (iv) , , ,
3 2 30 15 5 15 2 10 22 11 66 33 8 32 16 4

OPERATIONS ON FRACTIONAL NUMBERS
You have already learnt to perform all the four operations of addition, subtraction, multiplication and division on
whole numbers. These operations can be performed with equal case on fractional numbers as well. To find out
how easy it actually is, go through these subtopics.

Addition and Subtraction of Two Like Fractions
For addition or subtraction of like fractions, only numerators are added or subtracted and the common denominator
of the given fractions becomes the denominator of the sum or difference.

Addition and Subtraction of Two Unlike Fractions
For adding or subtracting two unlike fractions, first change them into like fractions and then the numerators are
added or subtracted. The common denominator obtained in the transformed fractions becomes the denominator
of the sum or the difference.

Let’s Attempt

4 2 17 5
Example 1: Add and · Example 2: Evaluate: -
11 11 73 73
4 2 42 6 ( 17 5 )
Solution: Sum = Solution: Difference = 17 5 12
11 11 11 11 73 73 73 73

1
1
Example 3: Evaluate 7 + 6 ·
2 2

Solution: Sum 7 1 6 1 76 1 1 (adding whole parts and fractional parts separately)

2 2 2 2

13 11 13 2 13 114
2 2

3 3 1 1
Example 4: Subtract 5 from 18 · Example 5: Find the sum: +
7 7 7 5
3
Solution: Difference = 18 - 5 3 Solution: L.C.M. of 7 and 5 = 35;
7 7
1 15 5 1 17 7
3 3 ,

= (18 – 5) + 7 75 35 5 57 35
7 7
Therefore,
= 13 + 0 = 13

1 1 5 7 57 12
·
7 5 35 35 35 35