Thanks, mtf. I’m aware of the basic math rules. And that’s why I was puzzled: I just couldn’t figure out how my code produced different answers if it was essentially the same as everyone elses, and the browser let me pass (green light). I now noticed, however, that I had inverted the order between d and c in the second variable (should be c minus d, and not d minus c). So problem solved anyway
Your replies in the forum have been very helpful over several Codecademy courses, thanks for taking the time!