Quiz Entry - updated: 2026.07.14
How do you quickly identify if a number is binary, decimal, or hexadecimal?
Only 0s and 1s = binary; digits 0-9 with no letters = decimal; contains letters A-F (or a 0x prefix) = hexadecimal.
Identification tips:
| Number System | Characteristics |
|---|---|
| Binary | Only contains 0 and 1 |
| Decimal | Contains digits 0-9, no letters |
| Hexadecimal | Contains digits 0-9 AND/OR letters A-F |
Common notation conventions:
- Binary: Often written with "0b" prefix or subscript ₂
- Decimal: Usually no prefix (default assumption)
- Hexadecimal: Often written with "0x" prefix or subscript ₁₆
Examples:
- 10101010 → Binary (only 0s and 1s)
- 192 → Decimal (digits only)
- A8 → Hexadecimal (contains letter)
Go deeper:
Wikipedia — Hexadecimal § Notation — the 0x / subscript conventions that signal which base a number is written in.