While I was waiting for the bus, I was wondering if I could calculate how many Earth years it would take for one of the Voyagers to travel 4 lightyears without looking anything up and from my head

My calculations came out on 72.000 earth years

When I looked it up it stated between 70.000 - 74.000 years so kinda spot on!

The math is quite simple I know but still I found it a tiny little win