Ch 4 · Binary Addition & Overflow · Theory

Topic 4 of 14 in Data Representation — How Computers Store Everything as Numbers — 2 lessons.

Adding Bits

Binary addition uses the same carry idea as denary, with four cases:

Overflow

An 8-bit number can only hold 0–255. If an addition needs a 9th bit, that bit has nowhere to go — this is overflow, and the stored answer is wrong.

All topics in Theory Data-representation

1. Why Computers Use Binary
2. Counting in Binary
3. Hexadecimal — Shorthand for Binary
4. Binary Addition & Overflow
5. Negative Numbers — Two's Complement
6. Logical Binary Shifts
7. Representing Text
8. Representing Images
9. Representing Sound
10. Storage Units & Compression
11. Floating-Point Numbers (A Level)
12. More Number Representations
13. File Organisation & Access (A Level)
14. Check Your Understanding