Topics from the Cambridge IGCSE (9-1) Computer Science syllabus.

1.1.1 | NUMBER SYSTEMS

Topics from the Cambridge IGCSE (9-1) Computer Science 0984 syllabus 2023 - 2025.

OBJECTIVES
1.1.1 Understand how and why computers use binary to represent all forms of data.

Any form of data needs to be converted to binary to be processed by a computer
Data is processed using logic gates and stored in registers

ALSO IN THIS TOPIC
YOU ARE HERE | 1.1.1 NUMBER SYSTEMS
1.1.2 NUMBER SYSTEMS
1.1.3 NUMBER SYSTEMS
1.1.4 NUMBER SYSTEMS
1.1.5 NUMBER SYSTEMS
1.1.6 NUMBER SYSTEMS
1.2.1 TEXT, SOUND AND IMAGES
1.2.2 TEXT, SOUND AND IMAGES
1.2.3 TEXT, SOUND AND IMAGES
1.3.1 STORAGE AND COMPRESSION
1.3.2 STORAGE AND COMPRESSION
1.3.3 STORAGE AND COMPRESSION
1.3.4 STORAGE AND COMPRESSION
TOPIC 1 KEY TERMINOLOGY
TOPIC 1 ANSWERS
TOPIC 1 TEACHER RESOURCES (CIE)

DATA REPRESENTATION

1.1.1 NUMBER SYSTEMS

Whilst computer are complex machines that are capable of a countless number of functions at an incomprehensible speed, when they are broken down to their most simple form, they are little more complex than a light switch. Imagine if you had just two light switches and represented a letter with each combination of the switch settings, you could represent 4 different letters.

When you press a key on your keyboard an electrical signal is sent to your computer and converted to a binary representation, a combination of switches being on or off. To make it easy for visual representation we represent the OFF state with zeros and the ON state with ones. For example, when you press the letter A on your keyboard the electrical signal is converted and stored as 01000001, the letter B is stored as 01000010.

Whilst at its core the computer is no more complicated than a light switch, when you combine billions of light switches with the hundreds of thousands of components that create your computer, impressive things can be done.

Every keystroke, pixel on your screen, image you upload, sound played by your computer is all converted to a binary representation to be stored and processed on your computer.

Every process your computer does can be broken down to its binary representation, the processor can process billions of operations per second and each binary value is stored in a very fast and very small section of memory called a register whilst it is waiting to be processed.

what is binary

A number system that uses only two digits, 0 and 1.

why do computers use binary

Any form of data needs to be converted to binary to be processed by a computer. Data is processed using logic gates and stored in registers.

What are some limitations of binary

It can only represent whole numbers and is limited by memory size and processing speed.

1: What is the main reason why computers use binary to represent data?
A) It is the most efficient way
B) It is the easiest way
C) It is the only way
D) It is the most convenient way

2: How does binary representation of data allow computers to perform calculations and logical operations?
A) By using specific arithmetic circuits
B) By using specific logic circuits
C) By using specific memory circuits
D) By using specific input/output circuits

3: What are the limitations of using binary to represent data in computers?
A) It can only represent whole numbers
B) It is limited by memory size
C) It is limited by processing speed
D) All of the above

4: What is the relationship between binary representation of data and the hardware of a computer?
A) The hardware is designed to work with binary data
B) The hardware is limited by binary data representation
C) The hardware has no relationship with binary data representation
D) The hardware can be designed to work with data represented in other forms besides binary

What is binary and how does it relate to computers?
Why do computers use binary to represent data?
Can a computer process data in any other form besides binary?
What is the significance of logic gates in computer processing?
How does data get converted into binary before being processed by a computer?
What role do registers play in storing data in a computer?
How does binary representation of data allow computers to perform calculations and logical operations?
What are the advantages of using binary to represent data in computers?
What are the limitations of using binary to represent data in computers?
What is the relationship between binary representation of data and the hardware of a computer?

NAVIGATION

1.1.1 NUMBER SYSTEMS | Why Computers use Binary
1.1.2 NUMBER SYSTEMS | Binary, Hex and converting between number systems
1.1.3 NUMBER SYSTEMS | Benefits of Hex
1.1.4 NUMBER SYSTEMS | Binary addition and Overflow
1.1.5 NUMBER SYSTEMS | Binary Shifts
1.1.6 NUMBER SYSTEMS | Negative Number representation, Two's Complement
1.2.1 TEXT, SOUND AND IMAGES | How Computer represent Text
1.2.2 TEXT, SOUND AND IMAGES | How Computers represent Sound
1.2.3 TEXT, SOUND AND IMAGES | How Computers represent Images
1.3.1 STORAGE AND COMPRESSION | How data storage is measured
1.3.2 STORAGE AND COMPRESSION | Calculating image and sound file size
1.3.3 STORAGE AND COMPRESSION | Purpose of Data Compression
1.3.4 STORAGE AND COMPRESSION | Lossy and Lossless, how files are compressed
TOPIC 1 KEY TERMINOLOGY
TOPIC 1 ANSWERS
TOPIC 1 TEACHER RESOURCES (CIE)