Changing units in cell?

[dylanemcgregor]

I often have data that is for numbers in the billions. For various reasons (table size, comparability between the numbers, etc...) I'd like to be able to change the display for the cell to be $b, or $m (and have the ability to quickly switch the formatting back and forth between the two) while having the whole value of the cell remain as the full number. So for example, the number 1,000,000,000 could be displayed as either 1 (if formatted as billions) or 1,000 (if formatted as millions) but the value would always be 1,000,000,000.

It seems something like this should be available via custom number formatting, but I haven't come across it there or anywhere else. Have I been missing something obvious?