Human have a total of 10 symbols to represent numbers: from 0 to 9. These can represent an infinite range of numbers. In the same way, just about anything in the universe can be represented with just 1s and 0s. We just need a system to combine them.

Imagine four switches that can either be turned on, or turned off. Each switch has its own value, ’8′, ’4′, ’2′ and ’1′. When they are all turned off, it represents 0 – 0000. To represent the number 1 we simply turn on the ’1′ switch – 0001. To represent the number 2, we turn off the ’1′ switch and turn on the ’2′ switch – 0010. Now think carefully – How is the number 3 represented? Turn on both the ’2′ and the ’1′ switch – 0011 – because 2 plus 1 equals 3.

Are you starting to understand the system behind counting in binary? Let’s try to get the number 7. Turn on switches ’4′, ’2′, and ’1′ – 0111. What about number 11? Turn on switches ’8′, ’2′ and ’1′ – 1011.

Look at the following table to understand how it works: