Using positional notation, how do you read a hex number directly as decimal?
Multiply each hex digit by its power of 16 (rightmost = 16⁰ = 1, next = 16¹ = 16, ...) and sum. Example: A8 = 10×16 + 8×1 = 168.
This is the direct shortcut that skips the binary detour — handy for the small two-digit hex values you meet most often, like a single address octet. It's the same positional principle as decimal (powers of 10) and binary (powers of 2), just base 16, which makes it a good mental model for why all three systems are really the same idea with a different radix. Remember to use each letter's value: A=10 ... F=15.
Hexadecimal positional notation:
- Each position is a power of 16: 16⁰ = 1, 16¹ = 16, 16² = 256, ...
- Multiply each digit's value by its position value
- Sum the results
Example: Convert A8 to decimal
| Hex Digit | A | 8 |
|---|---|---|
| Position Value | 16¹ = 16 | 16⁰ = 1 |
| Digit Value | 10 | 8 |
| Calculation | 10 × 16 = 160 | 8 × 1 = 8 |
Result: 160 + 8 = 168
Why it matters: this is the same positional-value idea as binary and decimal, just base 16 — a fast way to read two-digit hex values like address octets.
Go deeper:
Wikipedia — Positional notation — the one principle (digit × baseⁿ, summed) that unifies decimal, binary, and hex.