How do two fractions have a sum of exactly 1? - Answers

If the sum of two fractions have the same number of numerator and denominator.Fraction is nothing but a part of 1. When we say 1/8 it means 1 has been divided into 8 equal parts.So if for example I consider it as a whole cake and cut it into 8 equal slices or parts and I eat 3 parts and you eat the balance, 5 parts, then the fraction which I eat is 3/8 and you eat is 5/8 and when we add both we get again 3/8+5/8 = 8/8 =1 i.e the whole cake we started with.Hence if the two fractions which you are adding are total number of equal parts a 1 has been divided into it will give you exactly one. For eg. 1/3 and 2/3, 2/5 and 3/5, 7/9 and 2/9 etc....It's easy to tell if the two fractions have a common denominator.In that case, their sum is exactly ' 1 ' if the sum of their numerators is equal to their common denominator.