As noted, I'm not much of a numbers person, so using Excel is a challenge on a good day. Sometimes it does things that just mystify me. For example, after a long absence from Excel, I entered some information into a spreadsheet and ended up with #### in one of the cells instead of numbers.
I'd put in a formula and figured that I'd just done it wrong. (That would not be unusual for me after all.) Oddly enough, I couldn't find # (pound signs) in the online help. Maybe it's there, but I couldn't find it. Anyway, at some point, I finally discovered that it means the data is just too wide to fit in the cell. The annoying pound signs actually just indicate a formatting problem. You also may end up with your number turned into scientific notation, so a huge number turns into something like 1E+20.
Once you actually know what the pound signs mean, the solution is easy. You just need to make the column wider. The easiest way to make an entire column wider is to place your cursor at the top of the column and click and drag to move the column divider over. (You can tell when your cursor is in the right place and you are able to drag the divider when the cursor turns into a double-sided arrow.)
I'm also a big fan of Excel's AutoFit command, which automatically resizes the cells to fit the longest item in the column. Click on the letter at the top of the column to highlight the entire column. Then choose Format|Column|AutoFit Selection. An even easier way to access AutoFit is to double-click at the top of the column on the divider (again when the cursor is a double-sided arrow).
Once you make the column wider, magically all the pound signs go away.