Binary Value

What is Binary?

Binary is a base 2 number system invented by Gottfried Leibniz where numeric values are represented by different combinations of 0 and 1, also known as OFF or ON.

Why do computers use binary?

Binary is still the primary language for computers because of the following reasons.

• It is a simple and elegant design.
• Binary's 0 and 1 method is efficient at detecting an electrical signal's off or on state.
• The positive and negative poles magnetic media is quickly translated into binary.
• Binary is the most efficient way to control logic circuits.

How to read binary numbers

The following chart illustrates the binary number 01101000. Each column represents the number two raised to an exponent, with that exponent's value increasing by one as you move through each of the eight positions. In this example, we get the total value by reading the chart from right to left and adding each column's value to that of the previous column: (8+32+64) = 104. As you can see, we do not count the bits with a 0 because they're "turned off."

Exponent:	27	26	25	24	23	22	21	20
Value:	128	64	32	16	8	4	2	1
ON/OFF:	0	1	1	0	1	0	0	0

The next example is 11111111 in binary, the maximum 8-bit value of 255. Again, reading right to left we have 1 + 2 + 4 + 8 + 16 + 32 + 64 + 128 = 255.

Value:	128	64	32	16	8	4	2	1
ON/OFF:	1	1	1	1	1	1	1	1

Note: Counting on a computer normally starts with 0 instead of 1. Therefore, counting all the bits does equal 255, but if you start at 0, it is really 256.