Forgot to put a zero in my gradebook

I have a student with a grade in the 40’s. She’s not doing well, but it’s not THAT bad. I just double checked all of her grades (I use an online gradebook) and everything is entered and correct. I enter grades as whole numbers (92, 85, 100, etc) so I know that I’m missing a zero somewhere. I just can’t seem to find it. I’ve been staring at her grades for almost an hour at this point. I don’t know if I’m just being paranoid or OCD, or if I really am missing something. Any suggestions on what I can do to find the problem? I really don’t want to wait until parent teacher conferences to find out I made a mistake.