The numbers 1660 to 1666 in roman numerals
The right column shows how each roman numeral adds up to the total.
| 1660 | = | MDCLX | = | 1000 + 500 + 100 + 50 + 10 |
| 1661 | = | MDCLXI | = | 1000 + 500 + 100 + 50 + 10 + 1 |
| 1662 | = | MDCLXII | = | 1000 + 500 + 100 + 50 + 10 + 1 + 1 |
| 1663 | = | MDCLXIII | = | 1000 + 500 + 100 + 50 + 10 + 1 + 1 + 1 |
| 1664 | = | MDCLXIV | = | 1000 + 500 + 100 + 50 + 10 + 5 − 1 |
| 1665 | = | MDCLXV | = | 1000 + 500 + 100 + 50 + 10 + 5 |
| 1666 | = | MDCLXVI | = | 1000 + 500 + 100 + 50 + 10 + 5 + 1 |