1.1

Number systems

10 flashcards to master Number systems

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Definition Flip

Define the term 'binary' and state its base.

Answer Flip

Binary is a number system that uses only two digits: 0 and 1. It's base 2, meaning each digit position represents a power of 2 (

Example: 2^0, 2^1, 2^2).
Definition Flip

Explain what 'denary' number system is and give another common name for it.

Answer Flip

Denary is the base-10 number system that humans commonly use. Each digit position represents a power of 10 (

Example: 10^0, 10^1, 10^2). It is also commonly called 'decimal'.
Definition Flip

Describe the hexadecimal number system and its base.

Answer Flip

Hexadecimal is a base-16 number system. It uses the digits 0-9 and the letters A-F to represent values from 0 to 15 (A=10, B=11, C=12, D=13, E=14, F=15).

Key Concept Flip

Convert the binary number 1011 to denary.

Answer Flip

1011 in binary is (1 * 2^3) + (0 * 2^2) + (1 * 2^1) + (1 * 2^0) = 8 + 0 + 2 + 1 = 11 in denary.

Key Concept Flip

Convert the denary number 25 to hexadecimal.

Answer Flip

25 divided by 16 is 1 with a remainder of 9. Therefore, 25 in denary is 19 in hexadecimal.

Definition Flip

Define the term 'bit'.

Answer Flip

A bit is the smallest unit of data in a computer, representing a single binary digit (0 or 1). It is the fundamental building block of all digital information.

Definition Flip

Define the term 'byte' and how many bits are in one byte.

Answer Flip

A byte is a unit of digital information that consists of 8 bits. Bytes are commonly used to represent characters, numbers, and other data in computer systems.

Definition Flip

Define the term 'nibble' and state how many bits is in one nibble.

Answer Flip

A nibble is a unit of digital information that consists of 4 bits. It is exactly half of a byte and is used in some applications.

Key Concept Flip

Give an example of where hexadecimal numbers are used in computing.

Answer Flip

Hexadecimal numbers are commonly used to represent memory addresses and colours in HTML and CSS.

Example: a color code might be '#FFFFFF' (white).
Key Concept Flip

Explain why computers use the binary number system.

Answer Flip

Computers use binary because electronic circuits have two distinct states, often represented by 'on' or 'off', which can easily represent 1 and 0. This simplifies the design and operation of computer hardware.

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Key Questions: Number systems

Define the term 'binary' and state its base.

Binary is a number system that uses only two digits: 0 and 1. It's base 2, meaning each digit position represents a power of 2 (

Example: 2^0, 2^1, 2^2).
Explain what 'denary' number system is and give another common name for it.

Denary is the base-10 number system that humans commonly use. Each digit position represents a power of 10 (

Example: 10^0, 10^1, 10^2). It is also commonly called 'decimal'.
Describe the hexadecimal number system and its base.

Hexadecimal is a base-16 number system. It uses the digits 0-9 and the letters A-F to represent values from 0 to 15 (A=10, B=11, C=12, D=13, E=14, F=15).

Define the term 'bit'.

A bit is the smallest unit of data in a computer, representing a single binary digit (0 or 1). It is the fundamental building block of all digital information.

Define the term 'byte' and how many bits are in one byte.

A byte is a unit of digital information that consists of 8 bits. Bytes are commonly used to represent characters, numbers, and other data in computer systems.

About Number systems (1.1)

These 10 flashcards cover everything you need to know about Number systems for your Cambridge IGCSE Computer Science (0478) exam. Each card is designed based on the official syllabus requirements.

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