I have the worst luck in regards to calculators.
I just tried to change the battery in my calculator for tomorrow… and it died! Switched both the new and the old battery back in and it won’t work anymore. 
Good thing I got two more extra calculators though…
My attrition rate with these things is horrendous. This is the fourth calculator I’ve lost/destroyed now. I also killed another one when I dropped it in the urinal prior to the exam a couple of years ago.
Still got two more backups for tomorrow though, so I’m living proof of having multiple calculators!
Good luck for tomorrow all.