Binary Math
Binary math works just like decimal math, except that the value of each bit can be only 0 or 1. To get a feel for binary math, let's start with decimal addition and see how it works. Assume that we want to add 452 and 751:
  452
+ 751
  ---
 1203
To add these two numbers together, you start at the right: 2 + 1 = 3. No problem. Next, 5 + 5 = 10, so you save the zero and carry the 1 over to the next place. Next, 4 + 7 + 1 (because of the carry) = 12, so you save the 2 and carry the 1. Finally, 0 + 0 + 1 = 1. So the answer is 1203.

Binary addition works exactly the same way:

  010
+ 111
  ---
 1001
Starting at the right, 0 + 1 = 1 for the first digit. No carrying there. You've got 1 + 1 = 10 for the second digit, so save the 0 and carry the 1. For the third digit, 0 + 1 + 1 = 10, so save the zero and carry the 1. For the last digit, 0 + 0 + 1 = 1. So the answer is 1001. If you translate everything over to decimal you can see it is correct: 2 + 7 = 9.

To see how boolean addition is implemented using gates, see How Boolean Logic Works.

Quick Recap

  • Bits are binary digits. A bit can hold the value 0 or 1.
  • Bytes are made up of 8 bits each.
  • Binary math works just like decimal math, but each bit can have a value of only 0 or 1.
There really is nothing more to it -- bits and bytes are that simple!

For more information on bits, bytes and related topics, check out the links on the next page.