In this unit, you'll learn how computers represent everything — numbers, text, images, sound — using just binary digits (1s and 0s). Although digital systems seem smart and complex, at their core they rely on incredibly simple operations. To store and process information, computers must convert it into binary, because their internal circuits can only detect two states: on and off. You’ll explore why this is such an efficient system, and how data is measured and manipulated in this form.
The unit is divided into three chapters. In Chapter 1, you’ll learn how data is measured and represented using different number systems. You’ll convert between denary, binary, and hexadecimal, calculate file sizes, and understand how overflow errors occur. These skills are essential for understanding how computers manage memory and storage.
Chapter 2 builds on that by introducing binary arithmetic and character representation. You’ll perform binary addition, use bit shifts to multiply and divide quickly, and discover how letters, symbols, and emojis are stored using character sets like ASCII and Unicode. This is where data becomes more human-readable, and where issues like encoding and bit limitations start to affect real software.
In Chapter 3, you’ll dive into multimedia — how images and sound are represented using binary, how factors like resolution and sample rate affect quality, and how to calculate file sizes. You’ll then learn about compression, both lossy and lossless, and how it helps reduce file sizes while balancing storage space and quality. This is especially relevant to apps you use every day, like YouTube, Spotify, or WhatsApp.
By the end of this unit, you’ll not only be able to convert and calculate using binary data, but also explain how your favourite media is stored, streamed, and compressed. These are core computing concepts that link closely to both real-world technology and programming.