1) You could treat each digit as an integer (or boolean) value:
Originally Posted by Teiji
2) You could declare them as char's, which really are small int's "under the hood").
scanf(" %d", &bit1); //etc.
If 'A' == 48, guess what 'A' + 'A' is? Hint: it's not AA!
Guess what you get when you print out a char with integer format, as in #1?
3) you could create your own data type.
Since it looks like you want to do some math on them, I'd be tempted to suggest #1, for you. Maybe put in into an integer array.
It all depends on what you want to do with the variables, and how comfortable you are (or if you want to stretch your C muscles), with those operations, on that data type.