Binary System and Introduction

What are Binary Numbers
In the word Binary, ‘Bi’ means two, so a system of numbers which involves only two digits is called binary system. The two binary numbers used are ‘1’ and ‘0’. The binary system works in the same way as the decimal system which consists of ten digits which are 0 to 9, in case of binary system there are only two possible digits 1 and 0. Any number which is expressed in the binary system would be a combination of the two digits, 1 and 0. It is mainly useful in the field of technology.  In an electrical circuit we have only two options which are ‘on’ and ‘off’ and hence based on this the binary system plays an important role in all the communications which take place inside a computer. In a decimal system the place values are ones, tens, hundreds, thousands, ten thousands and so on. These values can be written as power of 10 which would be 10^0, 10^1, 10^2, 10^3, 10^4 and so on. In the same way the binary system starts from the right and proceeds towards left the difference being the base is 2.

Binary Numbers Chart can be given as below
2 raised to power zero = 2^0=1
2 raised to power one = 2^1=2
2 raised to power two= 2^2=4
2 raised to power three=2^3=8
2 raised to power four = 2^4=16
2 raised to power five= 2^5=32
2 raised to power six = 2^6=64 and so on, in general it can be considered as 2 raised to power x = 2^x
For example, let us consider a binary number 1011 and convert it into decimal form
Binary conversion: 8   4   2    1
      Decimal form:  1   0   1    1
1011(base 2) = 1x(8) + 0x(4) + 1x(2) + 1x(1) = 8+0+2+1=11(base 10)

List of Binary Numbers are as follows
0000=0; 0001=1; 0010=2; 0011=3; 0100=4; 0101=5; 0110=6; 0111=7; 1000=8; 1001=9; 1010=10 and so on.
Subtracting Binary Numbers
While subtracting binary numbers the following are the facts to be remembered:
0 – 0 =0 ;  1 – 0 = 1; 1 – 1= 0 and 10 – 1 is equivalent to 2 – 1 = 1 in binary system
Subtract 1011 from 10101.

0110 0110 1
-  1   0 1 1
__________
          1  0 1 0        
(1 -1 =0; 10 – 1 =1;0 – 0 = 0; 10 – 1 = 1 and 0 = 0 which gives 1 0 1 0)
Binary number      10101   -    1011 = 1010
Decimal equivalent   21       -       11   =10