I get that math if it explicitly said that this is a 1 year loan - but it doesn't. How do you know this wasn't a 4 year loan? and you pay $103 per month for 4 years?
or how do you know that this wasn't an "interest only loan" and you pay $103 in interest every month... and if you want to pay down any principle, then that would be anything that you pay above $103/month.