◌ 0B: no body contribution. The dotted rectangle marks a zero body contribution; the dotted square marks a zero flag contribution. Square brackets group the parts of one numeral. These placeholders are teaching aids, not the numeral zero or characters to insert into the final answer. Bare flags show flag contributions; complete numbers keep their normal bodies.
Brackets beside a numeral show its components: [flag + body]. The complete numeral remains outside the brackets. Paired arrows show where value moves during promotion or demotion.
6. Addition
Method: Operate on flags and bodies independently. Apply Flag Promotion or Place Promotion when needed.
Clean case: 6 + 7
| 6 = 5F 1B | [+] |
| 7 = 5F 2B | [+] |
| ────────── | |
| Flags: 5F + 5F = 10F | + = |
| Bodies: 1B + 2B = 3B | + = |
| Result: 10F 3B = 13 ✓ | [ + ] → |
With Flag Promotion: 9 + 4
Flag → Body →
| 9 = 5F 4B | [+] |
| 4 = 0F 4B | [+] |
| ────────── | |
| Bodies: 4B + 4B = 8B → Flag Promote → 5F + 3B | + = → + |
| Flags: 5F + 0F + 5F (from promotion) = 10F | + + = |
| Result: 10F 3B = 13 ✓ | [ + ] → |
With Place Promotion: 15 + 7
+ → in the twenties
Units body →
Units body →
| 15 = 15F 0B | [+◌] |
| 7 = 5F 2B | [+] |
| ─────────── | |
| Bodies: 0B + 2B = 2B | ◌ + = |
| Flags: 15F + 5F = 20F → Place Promote → 1B in twenties, 0F in units | + = Carry 1 to the twenties; no flag remains in units. |
| Result: 0F1B (twenties), 0F2B (units) = 22 ✓ | [ + ] twenties [ + ] units → |