Computer-science_A-level_Cie
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computers-and-components6 主题
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logic-gates-and-logic-circuits2 主题
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central-processing-unit-cpu-architecture6 主题
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assembly-language-4 主题
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bit-manipulation1 主题
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operating-systems3 主题
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language-translators2 主题
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data-security3 主题
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data-integrity1 主题
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ethics-and-ownership3 主题
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database-concepts3 主题
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database-management-systems-dbms-1 主题
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data-definition-language-ddl-and-data-manipulation-language-dml1 主题
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computational-thinking-skills1 主题
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algorithms14 主题
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data-types-and-records2 主题
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arrays2 主题
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files1 主题
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introduction-to-abstract-data-types-adt1 主题
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programming-basics1 主题
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constructs2 主题
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structured-programming1 主题
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program-development-life-cycle2 主题
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program-design-2 主题
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program-testing-and-maintenance3 主题
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user-defined-data-types1 主题
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file-organisation-and-access-3 主题
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floating-point-numbers-representation-and-manipulation3 主题
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protocols2 主题
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circuit-switching-packet-switching1 主题
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processors-parallel-processing-and-virtual-machines5 主题
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boolean-algebra-and-logic-circuits4 主题
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purposes-of-an-operating-system-os3 主题
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translation-software3 主题
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encryption-encryption-protocols-and-digital-certificates3 主题
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artificial-intelligence-ai4 主题
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recursion1 主题
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programming-paradigms4 主题
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object-oriented-programming7 主题
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file-processing-and-exception-handling2 主题
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data-representation5 主题
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multimedia3 主题
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compression2 主题
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networks-and-the-internet11 主题
uses-of-number-systems
Applications of Binary Coded Decimal (BCD)
What are the uses of binary-coded decimal (BCD)?
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Use Case |
Why BCD is used |
|---|---|
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Electronic calculators |
Keeps numbers in decimal format for easier display and accuracy |
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Digital clocks and watches |
Time is naturally decimal (e.g. 12:45), so BCD makes display logic simpler |
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Banking and financial systems |
Avoids rounding errors when doing decimal calculations, especially with money |
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Old digital systems / embedded systems |
Simpler to implement with hardware that displays digits individually |
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Binary coded decimal is commonly used in systems that need to display decimal numbers clearly and accurately
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BCD is ideal for applications like digital clocks, calculators, and financial systems where decimal precision matters
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Using BCD avoids rounding errors that can occur in binary-based arithmetic, especially with money and time
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It’s still found in older or embedded systems where simple hardware-based decimal output is needed
Applications of hexadecimal
Why is hexadecimal used?
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In Computer Science hexadecimal is often preferred when working with large values
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It takes fewer digits to represent a given value in hexadecimal than in binary
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1 hexadecimal digit corresponds 4 bits and can represent 16 unique values (0-F)
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It is beneficial to use hexadecimal over binary because:
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The more bits there are in a binary number, the harder it makes for a human to read
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Numbers with more bits are more prone to errors when being copied
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Examples of where hexadecimal can be seen:
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MAC addresses
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Colour codes
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URLs
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MAC addresses
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A typical MAC address consists of 12 hexadecimal digits, equivalent to 48 digits in in binary
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AA:BB:CC:DD:EE:FF
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10101010:10111011:11001100:11011101:11101110:11111111
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Writing down or performing calculations with 48 binary digits makes it very easy to make a mistake

Colour codes
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A typical hexadecimal colour code consists of 6 hexadecimal digits, equivalent to 24 digits in binary
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#66FF33 (green)
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01000010:11111111:00110011
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URL’s
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A URL can only contain standard characters (a-z and A-Z), numbers (0-9) and some special symbols which is enough for basic web browsing
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If a URL needs to include a character outside of this set, they are converted into a hexadecimal code
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Hexadecimal codes included in a URL are prefixed with a % sign
Responses