For 2's complement, substraction process by computer.
176-253=176+(-253)
176=10110000
253=11111101
253(inverse)=00000010
253(complement)=00000010+1=00000011
-253=253(complement)=00000011
176+(-253)=10110000+00000011=10110011=179?
but in fact 176-253=-77
is anybody tell me what's wrong here?