If we have a number n4n3 n2 n1 n-1 n-2 n-3 and base or radix is b so the value of the number is
n3*b3 + n2 *b2+ n1 *b1+ n0 *b0 + n-1 *b-1+ n-2 *b-2
So we can vary the value of b to get a different number system. We specify the value of the base as suffix to the number to represent which number system is being used. There are following number systems which are generally used to represent a value.