Those who have studied entry level networking are at least somewhat familiar with the concept of binary. Computers, based on registers or switches that only have two possible values, are well represented by the two possible values of a binary digit. Many people simply memorize the bit position values and convert between binary and decimal as required.

### Bit Position Values

*(128) (64) (32) (16) (8) (4) (2) (1)*

Using the above positional values (and aligning on the right), a binary number like 0110, could be converted to a decimal number of 6. If that’s confusing, there’s lots of examples and explanation on the Internet.

This article is about using unconverted binary values in basic math. Even though binary values are represented differently, it is still possible to add, subtract, multiply and divide. The rules are basically the same as those learned in elementary school. It is important that no digit can be greater than 1. If the calculated result is a “2”, its actually requires two digits and would be represented as “10”.

Below are some binary examples that demonstrate and check the use of elementary math procedures.

As demonstrated, the mechanics of math remains the same. With decimal, 9 + 1 is 10. With binary, 1 + 1 = 10. We simply have fewer possibilities to work with in each bit position. Once that becomes clear, the basic mathematical operation is basically the same. It should be noted that doing arithmetic with binary is not really a concept that is required for any of the Cisco certifications. However this mental exercise may help with binary familiarity. That familiarity can ultimately be beneficial.

That was fun, thank you.