Tutoring?

I am a first grade teacher and I'd like to make some more money on the side through tutoring. I am stuck, however, on how to 'advertise' myself in a flyer or post on a bulletin board. One of my BAs is in English, so I feel comfortable tutoring up to high school English, for example. On the other hand, I really suck at Math and it would make me nervous to tutor even a 5th grader at Math (I know, I know... I'm a teacher ... but in first grade we only add and subtract up to 20! haha).

Do I just let people call me, and then turn them down if I don't feel comfortable? Is there some way of weeding out certain needs that people have? The tutoring rate is pretty expensive here, and I want to feel like I am helping someone, not being stressed out because I feel uncomfortable with the material.

I hope this makes sense! Have any of you tutored?