Answer:

The word binary means composed of two. Binary numbers are numbers in base two. They are written with two digits 0 and 1 using groupings of two, four,(two twos), eight (two fours), etc.

For example 1101_two stands for 1 eight, 1 four, 0 twos and 1 unit, which is 13 in base ten

Computers use binary numbers. In an electric circuit, numbers can be represented by a current flowing (1)or not flowing (0).

When writing binary numbers you will need to signify that the number is binary.

For example take the value 101, as it is written it would be hard to work out whether it is a binary or decimal (denary) value, to get around this problem it is common to denote the base to which the number belongs by writing the base value with the number, for example: 101₂ 2 is a binary number and 10110 is a decimal (denary) value.

One other thing about binary numbers is that it is common to signify a negative binary value by placing a 1 (one) at the left hand side (most significant bit) of the value, this is called a sign bit, we will discuss this in more detail in the next part of the tutorial.