iGCSE Computer Science - Distance Learning

Tutor Marked Assignment 6
Tutor Marked Assignment 8 (Programming)

Binary Number Systems

The data representation topic deals with the fundamental way that computer systems store digital information. This section includes many of the maths concepts that underpin computer science including how the binary number system is used to store many different types of digital data.

Binary is the representation of the language that your computer speaks – in fact, instead of 1s and 0s your computer uses a pattern of on and off electrical signals that it can then translate into numbers.

An important thing to remember about computers is that they are actually very simple when you look at them closely – all they can do is count to 2, add, and shift numbers along.

So, how can they possibly hold that word-processed document that you’re typing? Or the photos from your phone? It’s all about combining very simple tasks into something more complex.

Before we start, it’s worth looking at our own number system. Since you started school (and probably before), you’ve been counting from 1 to 10 using a system called Denary. Den in latin means ten, and we have ten digits in our number system ranging from 0 to 9. So it makes sense that Bi meaning 2, would have two digits ranging from 0 to 1.

So binary if binary means to count to the second digit, then to make bigger numbers we just need more columns. In the example below, we can count up to 10.

Watch the video below on why binary numbers are important to all computer systems: