Excel automatically drops precision from .csvs

I've just noticed an issue that could be problematic (and hopefully hasn't come up yet). When editing a .csv, for numbers with extremely large values, Excel decides to truncate the value without warning.

E.g.: https://github.com/devinit/digital-platform/commit/72e1e39dbff39c171d318e9234f29bc8f1ad4595

In this case, I just changed the title names and saved. When I opened up GitHub, I noticed that two rows had also been edited. It automatically changed 1.30835x10^11 to 1.31x10^11. In this case, a difference of $165,000,000. The only way I was able to edit the column headings without having excel automatically drop the precision was by using Notepad. I don't know how we can ensure this hasn't happened in the past, and I'm not sure what the best way is to prevent it from happening in the future.