Instead of octodecim for 18, their writers use duodeviginti, and undeviginti instead of novendecim. ... Taking the symbol C for 100, and 10 for 500, by postfixing 0 once, twice, thrice, aamp;c, to 10 ; the symbols I00agt; I000agt; 10000. ... In fact , they never were employed for that purpose. ... With such an instrument, it is not difficult to perceive how addition and subtraction might be performed with ease and expedition, anbsp;...
|Title||:||Elementary arithmetic, with brief notices of its history|