Education

Roman Numbers

You can see numbers everywhere. Life is miserable without numbers in this digital world. When we have a look at our past the Romans made use of distinct numbers. But the mesmerizing part is till today we can see these numbers in use. Ex: On the clocks, as chapter numbers, etc. Let us learn about these roman numbers or numerals now.

The Roman numerals make use of seven Latin letters. The letters are I, V, X, L, C, D, and M standing respectively for 1, 5, 10, 50, 100, 500, and 1,000 in the Hindu-Arabic numeral system.

The combination of these letters or symbols are used to write various numbers. 

Rules to Write Roman Numerals

There are some simple rules to make it easier to write Roman numbers. They are as follows:

  • Add the numbers if the smaller numbers follow the larger numbers. 

Ex: In the Roman numeral XV, you add 10 and 5, which makes it 15.

  • Subtract the smaller number from the larger number when the smaller number precedes the larger number.
    Ex: In the Roman numeral IX, you subtract 1 from 10, which makes 9.
  • You cannot use four identical letters in a row while writing Roman numbers.

Ex: VVV is 5+5+5 = 15. For writing 20 you don’t use VVVV, instead we write it as XX.

  • To represent bigger numbers, use a line on top of the letter. This indicates that the number should be multiplied by thousand.

Ex: X = 10 1000 = 10000.

  • You can use both uppercase and lowercase letters to write /roman numbers.

Ex: VI = vi = 6.

  • Let us write Roman numbers from 1 to 20 using the above mentioned rules.

1 – I, 2 – II, 3 – III, 4 – IV, 5 – V, 6 – VI, 7 – VII, 8 – VIII, 9 – IX, 10 – X, 11 – XI, 12 – XII, 13 – XIII, 14 XIV, 15 – XV, 16 – XVI, 17 – XVII, 18 – XVIII, 19 – XIX, 20 – XX.

Translating Roman Numerals

For translating longer Roman numbers, you have to break them into parts. Ex: To translate MMCDXVII a number, you can follow these steps

  1. M is for the thousands (1000). Hence MM = 2000
  2. CD is for the hundreds (500 -100 = 400).
  3. X is for the tens, where X = 10.
  4. VII is for the ones (5 + 1+1 = 7).

By adding all these we get 2000 + 400 + 10 + 7 = 2417.

Worked Examples:

Example 1: Rihan wants to know if it’s time for his music class or not. He has his class at 7 o clock. Will you help him? The shorthand of the clock passed the roman numeral VI and the long hand points at VI. What hour is it?

Solution: The shorthand of the clock crossed VI = 6, and the long hand is pointing VI = 6. Hence the time is 6.30. So Rihan has still 30 minutes left for his music class. 

Example 2: Find the Value of DCXVI + (LVIII – X) + XXXV.

Solution: DCXV = 500+100+10+5 = 615, LVIII = 50+5+3 = 58, (LVIII – X) = (58 – 10) = 48, and XXXV = 10+10+10+5 = 35. 

Hence DCXVI + (LVIII – X) + XXXV = 615 + 48 + 35 = 698 = DCXCVIII.

Example 3: Write in Roman numbers: 10485.

Solution: 10000 = X , 400 = CD, 80 = LXXX and 5 = V

So 10485 =  XCDLXXXV.

Thus you write the numbers in Roman, you can learn more about Roman numbers by attending online math classes at Cuemath. For more details visit their website. 

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