Page 41 - Math_Genius_V1.0_C7_Flipbook

D:\Surender Prajapati\CBSE_ICSE_Book_New\CBSE\Grade-7\Math_Genius-7\Open_File\02_Chapter\02_Chapter
\ 15-Nov-2024 Surender Prajapati Proof-6 Reader’s Sign _______________________ Date __________

Division of Fractions

Division of a Fraction by a Whole Number

To divide a fraction by a whole number, we multiply the fraction by the reciprocal of the whole
number.
Rule: Fraction ÷ Whole number = Fraction × Reciprocal of whole number
1
= Fraction× Wholenumber

For example:
1 4
(a) ÷ 3 (b) ÷ 9
3 7
↓↓ ↓↓
1 1 1  1 4 1 4
= × =  QRecipriocalof 3 is  = × =  QRecipriocalof9 is 1
3 3 9  3 7 9 63  9 

Division of a Whole Number by a Fraction

To divide a whole number by a fraction, we multiply the whole number by the reciprocal of the
fraction.
Rule: Whole Number ÷ Fractional Number = Whole Number × Reciprocal of the Fractional Number.

For example:


(a) 4 ÷ 1 = 4 × 3 QReciprocal of 1 is 3  (b) 16 ÷ 2 = 16 × 5  QReciprocal of 2 is 5 



3  3  5 2  5 2
= 12 16 5
= × = 40
1 2
Division of a Fraction by Another Fraction

To divide a fraction by another fraction, we multiply the first fraction (dividend) by the reciprocal
of another fraction (divisor).
Rule: I fraction ÷ II fraction = I fraction × Reciprocal of the II fraction

a c a c a  c  a d ad
In general, if and are two fractions, then ÷ = × Reciprocal of  = × = .

b d b d b  d b c bc
1 2 1 2 1 5 15 5
×
For example: (a) ÷ = × reciprocalof = × = =
×
3 5 3 5 3 2 32 6
1 2 Wherever mixed
6 12 6 12 6 38 2
fractions are used, in
(b) 19 ÷ 38 = 19 × reciprocal of 38 = 19 × 12 = 2 = 1 Note: division first change
1 2 them into improper
Example 9: Divide the following: fractions.
121 3 5 1 2
(a) 11 ÷ (b) ÷ (c) 2 ÷
200 4 8 4 7

39 Fractions and Decimals