In this method, first we find the value of a single unit for the problem and then find the exact value by multiplying that single unit value for that problem. Ex: Let a man eats 8 mangoes in 4 days. How many mangoes will he eat in 10 days? Solution: In 4 days man eats 8 mangoes. So in 1 day, man will eat = 8/4 = 2 mangoes So in 10 days , man will eat = 2*10 = 20 mangoes. In this way, unitary method works.