inconsistent use of binary vs decimal units (MB vs MiB)

I received a report about U1 using binary units and decimal units inconsistently and perhaps incorrectly:

"The upload window correctly labels the size with "MiB", but everywhere else on the site says "MB" even though it is actually showing MiB."

This seems like a pretty low priority to fix, but it's also probably a very easy fix. Quick visual scan to check if it's dividing by 1000 or 1024, and a search-and-replace.