Sims having rough exam days regardless of studying

What do you mean by rough? Are they not doing well on the exams, or just stressed out? I think it’s designed to always be stressful, but if you’ve kept up with the class, you generally do well. I do tend to send my sim early if living on campus, just because I don’t want them late on exam day. Even off campus, I’ll send them outside to stand near the spawn point…

I'm talking about high school years! After the school day is over, i always they always get the moodlet saying that they had a rough day and that they should study more

Steffi0​  For high school, exams are every Friday.  I have found that if I send the teens down the rabbit hole to school, they do much better on their exams than they do if you join them at high school.  They also don't need to study when I do that.  I haven't noticed if they get the moodlet you mentioned though.   

Hope this helps.

Thanks! I'll try sending them to the rabbit hole school next time