You are there to help, to blend, not to take the lead in the class dynamics. Try to blend. If that doesn't work, draw pictures, draw all over the paper. Again with math, make them do examples. If they're doing homework or a worksheet and they don't get it, they won't be excited about doing more problems than they have to, but present it like it's part of your explanation of how to do it.
Some repetition is key to being able to do the math, that's how the system is set up.
Even if it gets a little frustrating, pick a small problem and keep trying different ways until they can get it on their own. If they don't know 6 x 7, teach them how to figure it out by adding six sevens or by adding two 3x7 's if they know their threes, whatever you do, don't say 42, and don't let them guess either. They feel so much more confident if they can feel like they did the problem themselves instead of being fed all the correct steps by you. Don't feel like you have to change the world through an hour or two of tutoring each week. For first time tutors, I would say that while you are there to help a student with academic work, it is extremely important to remember that this student should be treated with respect.