Ever needed to convert from Arabic numbers to Roman numbers? - or the other way round? - Well why don´t you just leap right over to www.novaroma.org/via_romana/numbers.html and start converting those numbers!
Yes, Arabs invented the numeral system we are using today -and they also came up with the bright idea of the "zero" - a symbol for the value of nothing. Guess we wouldn´t have had computers without that discovery...