Do you want to spend the rest of your life saying "do you want fries with that"?
Now granted there is nothing wrong with any honest work and I'm not saying anything bad here about fast food employment but the simple fact of life is without a high school diploma (at the very least) you will have very few options in life when it comes to a job. Considering how many waking hours of your day is spent earning a living, do you really want to spend it doing something you hate just because you don't have any other choices? That, my dear, will make a math class you don't enjoy seem like a breeze believe me.