When to give up on math? How do I know when I should give up on math? I can't pass any of my math tests no matter much I study, I have tutors, attend office hours and I still can't do better than a D on any test. Most of the advice I hear is take the class two or three times which is ridiculous to me. It just seems that I am not good at math for whatever reason. I put at least 15 hours a week into math studies outside of class and this is only an entry level college algebra class. 
I was planning on an engineering degree because I don't know how to pick a major other than picking one so I need math.
 A: First of all, the only one that can answer as to when to give up on math is you yourself. We will have incomplete information regarding your abilities, and most importantly your passion.
With that said, I, personally, don't think you should give up. People will be glad to answer your questions regarding problems you have. It can never be guaranteed that you will pass exams with perfect marks, or at all. But if you really love mathematics, or engineering for that matter, try to do it! If it won't work out at all, at least you will have tried. Giving up a passion is such a shame. 
And of course there's always the hard decision as to what to do to get a job after your exam. I have no answers on this to give you, and I don't think anyone here will have one either. It's up to you what to do, does this make you happy? Do you think you can get a career you will be satisfied with? 
Ask questions here and we will do our best to help you!
A: *

*You should be aware that 15 hours per week is not a lot when you missed out on math during all your high school time. Just imagine that other students put in, say, 5-10 hours per week during their high school years and that you have to make up for this lost time. It will take a year of working 15 hours per week to just be at their starting level, but unfortunately, it is not clear that you are trying to plug the holes in your knowledge before building on it. Why do you expect to be at the same level as students who actually learned something during high school?

*For me, the red flag in your post is not that you get a D, but that you do not seem to know before the test that you have not properly learned the content of the course. Did you feel that you had understood the course before the test? If yes, did you discuss with your tutors/professors where your self-assessment goes so wrong? If no, well, what is it that you do not understand and why don't you give us a concrete example.

*Another possibility of course, is that you understand mathematics, but have legasthenic-like problems with calculations, but I guess that you would have mentioned if you tend to interchange digits or have trouble with basic arithmetic
My suggestions:
a. Look at a site like Alcumus to practice some basics
http://www.artofproblemsolving.com/Alcumus/Introduction.php
(Note that not all of the problems there are simple but many are and they come with difficulty levels.)
b. Try to pinpoint your problem and ask a more precise question.
