I think my Latin teacher typed in a B+ instead of a C+, although my science teacher often screws up and it goes worse for me, which shows it can go either way.
How about you guys?
Yes, my history teacher once gave me an F as a midterm grade :0
Haha, it lowered my semester grade drastically under I told the admin to fix it! It was right before the mid-year report was about to be sent to colleges.
Yes it has happened so many times before and I just go to the teacher and ask them to fix their error but now it gives me anxiety because I never know if the grade is right or not
My Honors Chemistry teacher once switched up my grade for another students when submitting progress report grades. Other student must’ve been awfully disappointed when he realized it was a mistake.
My Pre-Calc teacher forgot to weight my entire bell’s semester grades last year, which for most people was the difference between adjacent letter grades. I was the only one who realized the problem, so my classmates were pretty pleased with me after that! 
Not exactly mistyping, but in eighth grade, my English teacher misheard my grade on a homework assignment as a 46/56 instead of a 26 (I had forgotten about the assignment and had randomly bubbled things in, since she had like six homework assignments per semester and forgetting one greatly affected your grade). I didn’t bother correcting her.
My math teacher accidentally switched around a few people’s grades after the curve, although it was pretty obvious (one had a 97, the other an 88) who was who. Thankfully, mine wasn’t one of them.
My language arts teacher put in a 10 instead of a 100, so I had a 50 in the class for a good two weeks.
my terrible and insane bio teacher last year gave me 6 zeros throughout the year for things i did and i had to correct her every time.
I briefly had a 690% in engineering because of an extra 0 added to 100 lol.
In ninth grade, one of my teachers put in a grade out of 100 instead of out of 10. So basically the entire class got x/100 or xx/100 instead of x/10 or xx/10. That caused all of our averages to be about 12 points lower - He fixed it after
Oh yes, my history teacher once made an assignment out of 105 instead of 95, but she changed it soon after.
I had a 69 on a few non-consecutive days back in my sophomore English class. I think my teacher was trying to tell me something.
my english teacher accidentally gave my friend a 2.5 for the final grade even though she had 4.0s for all four quarters.
My chemistry teacher gave me a 109/10 on an assignment, which brought my grade from a 105% to a 143%. I just emailed him and told him to fix it :disagree:
I had a teacher give me a 200% on an assignment. I asked her about it and she actually gave me that grade on purpose because she said I deserved it.
@bubba5274 Awesome! Wish I had a teacher like that!
Apparently I never said that I got a 1090% on that assignment, but you math whizzes probably figured that out anyway 
Fortunately, we have school loop at my school, so I just obsessively monitor my grades at all times haha. I’ve had teachers mistype grades before, sometimes it’s little stuff like 23/30 instead of 25/30, although once my math test got put in as a 78 when I actually got 100! I’ve also been given extra points, which I’ll usually tell the teacher about (depends if I need them haha) because I feel bad about points that I didn’t earn.
@DogsAndMath23 I use School Loop too!
Wait… your MATH teacher typed in your test wrong? I know, nobody’s perfect, but it was just funny.
@The5458Captain
Yeah, haha. The person above or below me on the grading sheet got a 78 and she accidentally typed in their grade for me, lol.