The numbers 1664 to 1670 in roman numerals
The right column shows how each roman numeral adds up to the total.
| 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 |
| 1667 | = | MDCLXVII | = | 1000 + 500 + 100 + 50 + 10 + 5 + 1 + 1 |
| 1668 | = | MDCLXVIII | = | 1000 + 500 + 100 + 50 + 10 + 5 + 1 + 1 + 1 |
| 1669 | = | MDCLXIX | = | 1000 + 500 + 100 + 50 + 10 + 10 − 1 |
| 1670 | = | MDCLXX | = | 1000 + 500 + 100 + 50 + 10 + 10 |