This key facts covers Quick Reference - Binary Arithmetic within Binary Arithmetic for GCSE Computer Science. Revise Binary Arithmetic in 3.3 Data Representation for GCSE Computer Science with 15 exam-style questions and 18 flashcards. This is a high-frequency topic, so it is worth revising until the explanation feels precise and repeatable. It is section 10 of 11 in this topic. Use this key facts to connect the idea to the wider topic before moving on to questions and flashcards.
Quick Reference - Binary Arithmetic
Addition Rules:
0 + 0 = 0 0 + 1 = 1 1 + 0 = 1 1 + 1 = 10 (0, carry 1) 1 + 1 + 1 = 11 (1, carry 1)
Shift Operations:
- Left shift 1: × 2
- Left shift 2: × 4
- Left shift 3: × 8
- Right shift 1: ÷ 2
- Right shift 2: ÷ 4
- Right shift 3: ÷ 8
Two's Complement Conversion:
- Flip all bits (0→1, 1→0)
- Add 1
- Done!
Number Ranges (8-bit):
- Unsigned: 0 to 255
- Two's complement: -128 to +127
Practice questions for Binary Arithmetic
In binary addition, what is the result of 1 + 1?
Explain the effect of a logical left shift and a logical right shift on the value of a binary number.