when we got our first bike computer, my husband enlisted the help of an engineer to help him set it up. There was a metric measurement in there, and no matter what they did, they couldn't figure out why it wasn't coming out right.
My 14 year old son came up and said, "those are centimeters, not millimeters, that bike tire would be gigantic with the numbers you're using"

He was able to visualize it, we were not.