The invention of negative numbers is based on the problems which the people in ancient times faced when they used to solve the negative solutions. The Chinese and the Indians used to work on numbers but they always had problems in solving negative solutions which they called as false problems. The invention of negative numbers was not like someone eventually invented it but it is based on the contributions of a number of people. Diophantus in the third century A.D. Called the equation 4x + 20 = 0, an absurd equation because it had the negative solution. This means that at that time there was no concept of negative numbers. Then Han Dynasty used red and black counting rods for denoting positive and negative coefficients. Then on the basis of his concepts the Chinese people solved the negative numbers.