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Knowledge/A Level/H446/01 Computer systems/Data Types/Represent positive integers in hexadecimal

Represent positive integers in hexadecimal

1.4.1 Data Types

Data Types — Note 5 of 10

Candidates need to have an understanding of the purpose and potential uses of Hexadecimal for example where and why they are used instead of binary and the benefits of using Hexadecimal over alternatives such as binary.

What you need to know

Hexadecimal (base 16) is a shorthand for binary used by people. Each hex digit represents exactly four bits, so long binary values can be written more compactly and with fewer errors.

What to know

  • Place values in two-digit hex: 16 1. Three digits: 256 16 1.
  • One hex digit represents one nibble (4 bits), so a byte is always two hex digits.
  • Uses: memory addresses, colour codes in HTML/CSS (e.g. #A2441B), MAC addresses, error codes and machine code listings.
  • Benefits over binary: shorter, easier for humans to read and remember, fewer errors when copying. It is easy to convert to binary, unlike denary.

Key terms

Hexadecimal

A base 16 number system using the digits 0 to 9 and the letters A to F (A = 10, B = 11, C = 12, D = 13, E = 14, F = 15).

Exam technique

  • Tip:Computers do not process hex. Hex is used by PEOPLE as a convenient way of representing binary.
← Previous noteAddition and subtraction of binary integers1.4.1 Data TypesNext note →Convert positive integers between binary, hexadecimal and denary1.4.1 Data Types

Back to Data Types

Data Types

Note 5 of 10

  1. 1Primitive data types: integer, real/floating point, character, string and Boolean
  2. 2Represent positive integers in binary
  3. 3Sign and magnitude and two's complement to represent negative numbers
  4. 4Addition and subtraction of binary integers
  5. 5Represent positive integers in hexadecimal
  6. 6Convert positive integers between binary, hexadecimal and denary
  7. 7Representation and normalisation of floating point numbers in binary
  8. 8Floating point arithmetic: addition and subtraction
  9. 9Bitwise manipulation and masks: shifts, combining with AND, OR and XOR
  10. 10How character sets (ASCII and UNICODE) are used to represent text
Topic overview