This is a very simple explanation of the binary system and its use in computing.  Far more is involved than the outline given here.  This is just to take some of the mystery out of "geek talk" for the normal computer user.  The detail can stay with the "experts"!
 

1.  THE DECIMAL SYSTEM

This is the normal way we count in every day life.  We start with 0, 1, 2, 3, 4, 5, 6, 7, 8 and 9, then we start over again with a 1 in front of each, then a 2, and so on.  We go in tens, hence the name DECIMAL system from the Latin 'decem' meaning 'ten'.  (Observant people will notice that this is the beginning of the name of the TWELTH month of the calender - why this is so is another story!)

Another slightly more mathematical way of looking at this is as follows.  Take the number 47 289 for example.  The '9' is in the units, or 1s, place.  The '8' is in the 10s place.  The '2' is in the 100s place.  The '7' is in the 1000s place and the '4' is in the 10 000s place.  This pattern continues for bigger numbers.  These places in the number are 10⁰, 10¹, 10², 10³, 10⁴, etc.

Still with it?  OK - so why is our system based on ten?  Who knows.  Perhaps it was because that's how many fingers we have, or maybe some other reason.  Well, what if there was some planet out there inhabited by little people with eight fingers?  How would they count?  You guessed it! They would go 0, 1, 2, 3, 4, 5, 6, 7, then 10, 11, 12, 13, 14, 15, 16, 17, then 20, 21, ... 27, 30, ... 77, 100, ... etc.  This could be called an octal system.  (Latin octem = 8)  If you have got this far and still follow you are doing well.
 

2.  THE BINARY SYSTEM

So what if we used hands rather than fingers?  Our system would be based on two digits instead of ten.  So we would count 0, 1, then start again adding 1 in front.  So we get 10,11.  Starting again from zero we would have 0, 1, 10, 11, 100, 101, 110, 111, 1000, 1001, 1010, 1110, 1111, etc.  All numbers in the binary system are made up of 0s and 1s.  Just as the places in a decimal number are 10⁰, 10¹, 10², 10³, 10⁴, etc., the places in a binary number are 2⁰, 2¹, 2², 2³, 2⁴, etc.  To see how to convert backwards and forwards between binary and decimal, have a look at some of the web sites listed below.

Note for the mathematical purist - Yes, I know that 2⁰, 2¹, 2², 2³, 2⁴, etc., are decimal numbers, and that their binary equivalents are 10⁰, 10¹, 10¹⁰, 10¹¹, 10¹⁰⁰, etc.!

Note for the non-mathematician - If you follow the note above, you are doing exteremely well!
 

3.  THE BINARY SYSTEM IN COMPUTING

What has all this got to do with computers?  Computers are simply complex machines which compute.  That is, they work with numbers.  All input into a computer is eventually reduced to a number, and a binary number at that.  This number is then stored as a number of memory locations which are either on or off.  Of course, it is not that simple.  There are many good books or web sites which can take you further into all this if you wish.  And, of course, we have not looked at Boolean Algebra where ones and zeros can represent TRUE or FALSE.  Or at the more complex hexadecimal system which also has its place in computing.
 

4.  WEB SITES

A couple of the many web sites available are as follows -
 

Would you like to find out how to play a great card game that uses the binary system?  Then click on this card -

 
 
 
 

THAT'S ALL FOLKS!
IF YOU GOT TO HERE - CONGRATULATIONS!
YOU ARE A SERIOUS PLAYER!

Page written by Robert Tanner, March, 2000.