"A lot of people are having problems with the order in which the arithmetic will occur (i.e. the order of the operators). When using other languages, I almost always use parenthesis to demonstrate to people reading the code (and to the interpreter / compiler) the order in which I want the arithmetic to occur... i.e. print "Hens", 25 + 30 / 6 print "Hens", 25 + (30 / 6) print "Roosters", 100 - 25 * 3 % 4 print "Roosters", 100 - ((25 * 3) % 4) PS Thanks to Fernando for PEDMAS - I've been programming (and occasionally teaching programming) since last century and never came across that before. PPS and thanks to Zedshaw, for an excellent resource" - martin english