Precisely as you have done so in your question.
CDLX
CDLX
460 = CDLX
460 000 000
460 = 4.6 × 102
To write a whole number as a fraction, you take the whole number over "one". 460/1 460 over 1
460.0
You cannot write fractions using Roman numerals.
You write 1533 in roman numerals like this: MDXXXIII
460
CDLX
To write twenty in Roman numerals, you simply write the letter X.
It is: 93,000,000 in Hindu-Arabic numerals