Please read the sentence faster.
To my surprise, that American's English writing was written better than mine, and I'm British.
Whenever I read a sad story I can’t stop crying for exactly two minutes and twenty seconds.
The kanji and the word are exactly the same. That means they share meanings as well.
You only had to learn one set of readings (on'yomi) for the parent kanji of this word. That means this word uses those readings as well, specifically the ぶん one when alone like this. You can remember this by thinking how whenever you're working on your writing, you get hungry and want to eat a "bun."