This key facts covers Hexadecimal to Denary Conversion within Binary & Hex for GCSE Computer Science. Revise Binary & Hex in 3.3 Data Representation for GCSE Computer Science with 16 exam-style questions and 22 flashcards. This is a high-frequency topic, so it is worth revising until the explanation feels precise and repeatable. It is section 10 of 15 in this topic. Use this key facts to connect the idea to the wider topic before moving on to questions and flashcards.
Hexadecimal to Denary Conversion
Method: Multiply place values (161, 160)
Example 1: Convert 3F to denary
Place values: 16¹ 16⁰
16 1
Hex: 3 F
3F = (3 × 16) + (15 × 1)
= 48 + 15
= 63 (denary)
Example 2: Convert 2A5 to denary
Place values: 16² 16¹ 16⁰
256 16 1
Hex: 2 A 5
2A5 = (2 × 256) + (10 × 16) + (5 × 1)
= 512 + 160 + 5
= 677 (denary)
Practice questions for Binary & Hex
Which of the following correctly describes the hexadecimal number system?
Explain why hexadecimal is used instead of binary when programmers write memory addresses and colour codes. Give three reasons.