Using Excel w/in Google Drive on an iPad Air

Hi,

I'm mainly a Windows user, but I was recently given this hand-me-down iPad Air. I installed Google Drive on it, and I've been using it to access a particular Excel 2013 spreadsheet that I've been working on. The problem I'm having is that if I need to switch to search something online quickly, I have to hit the Home button to get back to the Home page, which, in turn, closes the Excel spreadsheet. I then have to go back to Google Drive in order to re-open Excel. This wouldn't be an issue, but it's rather slow, and it sometimes hangs, which causes me to have to back out and re-launch. I've tried Google Drive online, and that that didn't help, b/c the functionality in the mobile version sucks, and the desktop version doesn't allow me to open anything for some reason. I also tried downloading GDrive, but that had zero functionality. Upon opening the spreadsheet, I might as well have been looking at a .jpg. I couldn't do anything w/ it. I'm basically out of ideas. Does anyone know how I can switch from the spreadsheet (preferably from w/in Google Drive) to another application w/out the spreadsheet closing? At this point, I'm willing to try anything. Any help would be greatly appreciated. Thank you!

Jeff