Decimal has no easy translation between a bit change and a number and you should entirely avoid using it when programming embedded systems. Also, even though computers can start counting from zero, don't make your customer also count this way. People start counting from one. Enough of the simplicity. Computers are generally very slow in doing multiplications and divisions and therefore you should try to avoid these instructions whenever possible.
Most computers allow operations on the individual bits of a number such as setting and clearing.
For a computer without direct bit control, the 'or' and 'and' operations are synonymous. You can easily relegate other tasks to bit manipulations. Odd and even numbers are a very simple case. Even numbers are those integers that are evenly divisible by two. You can easily test to see if a number is even by checking the first bit.