Fraction is defined as part of a whole. Ex: 35
Just take a chocolate bar and you want to share it with 5 people. What would you do ? You would make 5 equal parts of chocolate. Then let us say, 3 of your friends do not want the chocolate, as they are eating something else. Hence, 3 parts will remain with you. So you are left with 35 th of chocolate with you
Say now how do convert this into decimals ? You divided the chocolate in 5 parts. Instead, if you had divided in 10 parts,planning to give 2 parts each to 5 friends. So 3 friends not taking it will mean you will be left with 6 small pieces. Hence it is 6 parts out of 10 which we write as 0.6.
So 35 = 610 = 0.6.