Roman Numbers are representation of numbers using Alphabets.
Roman NumbersIVXLCDM
Indian Numbers1510501005001000



Rules:

1) If the letter is repeated , its value is added as many times as it is repeated .
example : XXX = 10+10+10 = 30

2) A letter of a smaller value, when written to the right of the letter of a bigger value, the smaller value is added to the higher value .
example : XI = 10 +1 = 11 
                LX = 50 + 10 = 60 
                CX = 100 +10 = 110 
                DC = 500 + 100 = 600
3) A letter of smaller value, when written to the left of the letter of bigger value, the smaller value is subtracted from the bigger value. 
Example : IX = 10 -1 = 9
               XL = 50 -10 = 40
               XC =100 -10 = 90
               CD=500-100 = 400

4) If a letter of a smaller value is placed between two letters of bigger value, then it is always subtracted from the letter of a bigger value on its right .
 Example:  XIV = 10 +(5-1) = 14
5) V, L and D are never repeated or subtracted .
 example = LC = 100 -50 -> 50 -> this is wrong. as 50 is wrtitten as L .
          VX =10-5 -> 5 -> this is wrong as 5 is written as V .
6) I can be subtracted from V and X only .

7) X can be subtracted from L and C only .

Exercise: Write roman numbers of numerals.
1)  40 = 50 -10 = XL
2)  60 = 50 + 10 = LX
3)  90 = 100 - 10 = XC
4)  290 = 100+100+100-10 CCXC
5)  230 = 100+100+10+10+10 = CCXXX
6)  490 = 400 + 90 = (500-100 )+ (100-10) = CDXC
7)  510 = 500+10 = DX
8)  988 = 900 + 80 + 8 = (1000 -100)+50+10+10+10+8 = CMLXXXVIII
9)  1010 = 1000 + 10 = MX

Exercise : Write numeral of Roman Numbers.
1)  LXXXIX = 50+10+10+10+ (-1 +10) = 89
2)  CXXV = 100 +10+10+5 = 125
3)  CDXCIX = (-100 + 500)+ (-10 +100) + (-1 +10) = 400+90+9 = 499
4)  CXC = 100 + (-10 + 100) = 100 +90 = 190
5)  DCLXXXVI = 500 + 100 + 50 +10+10+10+5+1 = 686
6)  XLIX = (-10 +50) +(-1+10) = 40+9 = 49
7)  CMXCIX = (-100 + 1000)+(-10 +100)+(-1+10) = 900+90+9 = 999



Q1.   Write the Roman Numbers for the Hindu-Arabic numbers .

a) 50   

b) 40   

c) 55   

d) 19   

e) 300   

f) 450   

g) 950   

h) 90   

i) 89   

j) 245   


Q2.   Write the Hindu-Arabic numbers for the Roman Numbers .

a) XIII   

b) XLIX   

c) XCIX   

d) CD   

e) DC   



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