Have you ever looked closely at that unruly balance on your MetroCard when the system flashes "Insufficient Fare" — you know, the kind that leaves you with $2.45, just a nickel short of another ride? It turns out that by purchasing cards in denominations pre-selected by the MTA, we've all been doing it wrong.
Luckily, Ben Wellington, of I Quant NY, has discovered (or rather, used simple mathematics) to determine shortcuts for buying a vending machine MetroCard without throwing money away in the process. With easy memorization (and spending an extra second to input an amount yourself), he suggests that you can get the most bang for your buck by using three "magic" numbers: $9.55, $19.05 and $38.10. Using his hack, the highest balance you'll ever have left on your card is $.03, compared to that awful $2.45 — which as Wellington points out, is pretty lucrative for the MTA, which gets the interest on that sum until you refill again and repeat the cycle.
So bookmark this page. Write these numbers down on something you won't lose. And, the next time you refill your MetroCard, you'll be on your way to saving a little cash and showing the MTA who's really boss. (I Quant NY)