There are a few rules for writing numbers with Roman numerals.
10 Rules for Writing Numbers and Numerals
3. Glad you were happy with my focus on the substance. I find the substance here very interesting whereas the rules for writing numbers in journal articles seems pretty boring to me.
Rules for writing numbers - English Grammar
3. In any case, I appreciate that you’re reacting to the substance of the post, unlike all the other commenters who are going on and on about the rules for writing numbers in text.
Numbers do not only show up in math assignments, but also in everyday writing. Like most things in the English language, there are rules for writing numbers. Yes, imagine that! There are certain numbers that we spell out in letters, while there are others that we only write in numerals (1, 2, 3, etc.). You have probably come across more than your fair share of ‘Top 10’ lists. Why is it not ‘Top Ten’ list? Keep reading to find out.There are only a handful of rules for writing numbers that virtually everyone agrees on. Two major ones: Numbers beginning sentences must be written out (Eight thousand twelve people attended the concert). Years (8 B.C., 2015) are expressed in numerals. But spelling out numbers vs. using numerals mostly comes down to policies and preferences that vary from publisher to publisher.Please note that there are some exceptions to the rules outlined below. As with other grammar rules, rules for writing numbers change according to certain style guides (i.e. Chicago Manual of Style, AP, MLA, etc.). However, here are some general rules for spelling out numbers.: A Grammar guide with Grammar Rules, Punctuation Rules, Capitalization Rules, Commonly Confused Words, Rules for Writing Numbers, Free Interactive English Quizzes, Grammar and Punctuation VideosThere are rules for writing numbers. The suggests you should “spell out a numeral at the beginning of a sentence.” It also suggests you should “spell out whole numbers below 10, use figures for 10 and above.”