<P> Two arithmetic books published in 1514--Köbel (left) using a calculation table and Böschenteyn using numerals </P> <Li> <P> Adam Ries, Rechenung auff der linihen und federn (2nd Ed .), 1525 </P> </Li> <P> Adam Ries, Rechenung auff der linihen und federn (2nd Ed .), 1525 </P> <Li> <P> Robert Recorde, The ground of artes, 1543 </P> </Li>

What single factor made the hindu-arabic number system superior to other number systems