How to separate the digits stored in a variable?

Answer 1

You can use an array of char type, also you can use type string to save your data, for instance:

int numberLength = 10;//defines how long is your number
char number[numberLength] = '0';
...
cin >> number;

Then you can access separate elements using array notation:
number[0] is a first digit of your number, ..., number[i] is ith element.

You can use string type as well. string type is better because you do not have specify how long your number is going to be!

#include
...
using std::string;
...
string number = "0";//your number initialized with zero
...
cin >> number;

You can access separate digits in the same way as for the previous case:

number[0] gives you first digit,..., number[sizeof number/sizeof number[0] - 1] gives you the last digit.