Roman numerals represent a number system that uses letters to express numbers collectively. The ancient Romans used the letters I, V, X, L, C, D, and M to write numbers. The Roman letters were used for the purpose of counting and performing other day-to-day transactions. The Roman letters are utilized as general suffixes for people across generations, as hour marks on a clock, to denote the names of Popes and Monarchs, etc.
Roman Symbols:
There are seven Roman symbols that are used to write thousands of different numbers. These symbols are Latin letters representing a specific value.
All other Roman numerals can be made using these seven Roman symbols.
We can simply represent 100 using C or 1000 using M.
Similarly, to write 200 in Roman numerals, we just add the letters “C + C”. So CC represents 200 in Roman numbers. And to write 2050 in Roman numerals, we will add the letters “M+M+L”. So MML will be the representation of 2050 in Roman numbers.
Rules for Writing Roman numerals:
Rule 1: When certain numerals are repeated, the number represented by them is their sum. For example, II = 1 + 1 = 2, or XX = 10 + 10 = 20, or, XXX = 10 + 10 + 10 = 30.
Rule 2: It is to be noted that no Roman numerals can come together more than 3 times. For example, we cannot write 40 as XXXX
Rule 3: The letters V, L, and D are not repeated.
Rule 4: Only I, X, and C can be used as subtractive numerals. There can be 6 combinations when we subtract. These are IV = 5 - 1 = 4; IX = 10 - 1 = 9; XL = 50 - 10 = 40; XC = 100 - 10 = 90; CD = 500 - 100 = 400; and CM = 1000 - 100 = 900
Rule 5: When a Roman numeral is placed after another Roman numeral of greater value, the result is the sum of the numerals. For example, VIII = 5 + 1 + 1 + 1 = 8, or, XV = 10 + 5 = 15,
Rule 6: When a Roman numeral is placed before another Roman numeral of greater value, the result is the difference between the numerals. For example, IV = 5 - 1 = 4, or, XL = 50 - 10 = 40, or XC = 100 - 10 = 90
Rule 7: When a Roman numeral of a smaller value is placed between two numerals of greater value, it is subtracted from the numeral on its right. For example, XIV = 10 + (5 - 1) = 14, or, XIX = 10 + (10 - 1) = 19
Rule 8: To multiply a number by a factor of 1000 a bar is placed over it.
Rule 9: Roman numerals do not follow any place value system.
Rule 10: There is no Roman numeral for zero (0).
Converting Numbers to Roman Numerals
Follow the steps below:
Step 1: Split the number to be converted into the least expandable form.
Step 2: Write their respective Roman letters.
Step 3: Add or subtract them.
For example, to write 2052 as a Roman numeral:
Step 1: 1000 + 1000 + 50 + 1 + 1
Step 2: M + M + L + I + I
Step 3: MMLII
So, 2052 in Roman numerals = MMLII
Converting Roman Numerals to Numbers
Similarly, we can convert Roman numerals to numbers by following these steps:
Step 1: Split the Roman numerals into single letters.
Step 2: Write their numerical value.
Step 3: Add or subtract them.
For example, to convert XVII to a number:
Step 1: X + V + I + I
Step 2: 10 + 5 + 1 + 1
Step 3: 17
So, the Roman numeral XVII represents number 17.
