What is a Binary Number? [Answered with Pictures]

Binary numbers are the life blood of computer.

You probably know what they look like:   a bunch of 1’s and 0’s.

Here are some non-examples of Binary numbers

  • example 1 :  12
  • example 2 :  31
  • example 3 :  15

Here are some examples of Binary numbers

  • example 1 :  101101
  • example 2 :  101
  • example 3 :  10

So how do you tell someone that your number is a binary Number?

I mean 10  could be a binary number or it could  “ten”?

In fact, there’s a well known joke that goes like this :

There are 10 types of people in this world. Those that know binary numbers and those that do not

The entire premise of this joke is that “10” could be a binary number meaning ‘2’,  but you would only know that if you understand how to convert binary numbers to decimal numbers.

Usually people write a subscript to indicate that a number is base 2 (binary) like this pictures:

The binary number ‘2’ looks ‘ten’ , so we put the base ‘2’ as a subscript
Picture of a binary number with base labelled
Another example of a binary number

So, that’s what Binary Numbers look like.

In the next post, we’ll talk about what it means to be a binary number (and how to convert binary numbers to ‘regular’ decimal numbers.)