PCO stands for Potential Change Order (construction management). Suggest new definition. This definition appears somewhat frequently and is found in the following Acronym Finder categories: 1  Business, finance, etc.
Quick Answer. The Roman numeral XIX is the number 19. X is the number 10, and I is the number one. When a lower number is placed in front of a larger number, it indicates subtraction; IX is the same as 10 minus one, which equals nine. The Ancient Romans used different letters to represent numbers.
For instance, a numeral VI with a line over it means 6000. Get Roman Numerals homework and study tips at Homeworktips.about.com. XXL is not a valid Roman Numeral. If youâre trying to write 30 it should be XXX.You can convert a whole number to roman numerals, or vice versa at Onlineconversion.com. The Basics: A smaller number in front of a bigger number means subtraction, all else means addition.For example, IX means 9, XI means 11.oman Numerals: 1  I-The numeral one. 2  II is two, III is three. 3  You rarely see IIII as 4, since IV can also mean 4, plus its shorter to write. 4  V-The numeral 5. 5  IV is 4, VI is 6, VII is 7, VIII is 8.