Suppose we are required to find the difference between 3abc and 7abc. We look at two scenarios. The value we would obtain by subtracting a larger quantity from the smaller quantity is not the same as one got by subtracting the lower value from the higher value. In the first scenario we have 7abc - 3abc which is 4abc. This is different from the value got in the second scenario which is 3abc - 7abc = - 4abc. Therefore, whenever a bigger value is subtracted from a smaller value, the process is as usual but to the solution part we prefix the minus sign, while the subtraction of a smaller value from a bigger value is nothing but the normal subtraction.