How do you say one to one hundred in roman numerals?

Answer 1

In todays modern notation of Roman numerals:-

Units from 1 to 9: I II III IV V VI VII VIII and IX

Tens from 10 to 90: X XX XXX XL L LX LXX LXXX and XC

Hundred: C

To select any number simply write them out in descending order as for example 99 = XC+IX = XCIX

Note that the ancient Romans would have probably worked out the Roman numeral system quite differently than we do today