The Roman Art of Counting

The basis of the Roman numerical system is counting on the fingers indicates that the Latin word "Jigitus" where we use word is derived from "digit" .Romans wrote numbers from one to four as follows

the symbol which represent five is v

may represent the gap between the thumb and the rest of the fingers

 In order to avoid writing number 4 ( iiii) ,they used the place value for symbol ,so if was written to the left of the symbol another symbol bigger than it means the Sum of the two numbers and is was written to the right of the symbol another symbol bigger than it means difference between the two numbers .numbers 6 , 7 , 8 are 

To write 10 they used symbol X , so by using the former rule 9 = IX , 11 = XI , 12= XII , 13= XIII , 14= XVI , 15 = XV , 16 = XVI , 17 = XVII , 18= XVIII , 19 = XIX , 20= XX and  30 = XXX 

 In order to avoid writing number 40 = XXXX they used L to represent 50 so 40 = XL , 60 = LX and so on. To write 100 they used symbol C ,so 90 = XC , 120 = CXX ,150= CL and 200 = CC. To write 500 they used D ,so CD = 400 , DC = 600 and 700 = DCC . They used M to write 1000 ,so 900 = CM , 1100 = MC and 1300 = MCCC.

now to write 1408 by using Roman counting system = MXDVIII 

To write 1564 = MDLXIV

To write 2010=  MMX.

Roman counting system remained popular in Europe until  the arab system Kharazmi appeared .The two systems are competing in Europe for almost four centuries, before the arab system prevailing because of it was easier than the other system in writing numbers and making operations with out using abacus which was  used roman counting system.

Mr Hesham