I write about transit at times here; it’s generally top of mind for me given my regular commuting. But a number of subway-related links have fallen into my drafts folder over the past few months, so for the time being Sundays are going to be dubbed “Subway Sundays” and I’ll be sharing some cool stuff around it.

This week’s post revolves around the unnecessarily complex math that has sometimes been needed to zero out a MetroCard, which is used to pay for subway rides. Fares are generally round enough – until last week they were $2.50, and just increased to $2.75 – but when you put money on your card, bonuses are also applied which don’t always line up. Continue reading →