Question

Roman figure rulrles

Answer 1

three times in succession to form the numbers.

(a) We know the value of I = 1, value of X is 10 and value of C is 100.


(b) The value of I, X and C are added as:

I = 1

II = 1 + 1 = 2

III = 1 + 1 + 1 = 3

X = 10

XX = 10 + 10 = 20

XXX = 10 + 10 +10 = 30

C = 100

CC = 100 + 100 = 200

CCC = 100 + 100 + 100 = 300

(c) No digit is repeated in succession more than thrice, i.e., I, X and C cannot be repeated more than 3 times.


(d) The digits V, L and D are not repeated. The repetition of V, L and D is invalid in the formation of numbers.


Rule 2: (a) When a digit of lower value is written to the right or after a digit of higher value, the values of all the digits are added. As:

VI = 5 + 1 = 6

VII = 5 + 1 + 1 = 7

VIII = 5 + 1 + 1 + 1 = 8

XI = 10 + 1 = 11

XII = 10 + 1 + 1 = 12

XV = 10 + 5 = 15

XVI = 10 + 5 + 1 = 16

LX = 50 + 10 = 60

LXV = 50 + 10 + 5 = 65


(b) Value of similar digits are also added as indicated inrule 1

III = 1 + 1 + 1 = 3


XXX = 10 + 10 + 10 = 30

XX = 10 + 10 = 20

Rule 3: When a digit of lower value is written to the left or before a digit of higher value, then the value of the lower digit is subtracted from the value of the digit of higher value. As:

IV = 5 - 1 = 4

IX = 10 - 1 = 9

XL = 50 - 10 = 40

XIV = 10 + (5 - 1) = 14 

XIX = 10 + (10 - 1) = 19

XXIX = 10 + 10 + (10 - 1) = 29

XLV = (50 - 10) + 5 = 45

CLIX = 100 + 50 + (10 - 1) = 159

However, V is never written to the left of X


Rule 4: (a) If we have to write the numbers beyond 10 we should write the number 10 or groups of number 10 and then number 1 or 5 as the case may be. Then these numbers are used to change to the corresponding Roman numerals. As:

12 = 10 + 2 = 1 0 + 1 + 1 = XII

20 = 10 + 10 = XX

22 = 10 + 10 +1 + 1= XXII

26 = 10 + 10 + 5 + 1 = XXVI

39 = 10 + 10 + 10 + (10 - 1) = XXXIX

37 = 10 + 10 + 10 + 5 + 1 + 1 = XXXVII


(b) According to this pattern, numbers higher than number 40 are also formed:

43 = (50 - 10) + 1 +1 + 1= XLIII

56 = 50 + 5 + 1 = LVI1

59 = 100 + 50 + (10 - 1) = CLIX

1238 = 1000 + 100 + 100 + 10 + 10 + 10 + 5 + 1 + 1 + 1 = MCCXXXVIII


Rule 5: If a horizontal line is drawn over the symbols or digits of Roman numerals, then the value of the numerals becomes 1000 times. As:

XV = 15 but XV = 15000, 

CLV = 155 but CLV = 155000