Go over each day's lesson with your second grader again. Repeating the rules learned during the day will help them stick so the student can remember them when doing problems. Since rules are the most important part of math, go over them as many times as necessary.
Ask the second grader if there were parts of the lesson that were not understood. Explain things in practical terms. For example, to explain simple fractions such as 1/2, 1/3 and 1/4, demonstrate using food such as fruit snacks or pieces of candy. Then give the child the snack for a little fun.
Help the student memorize basic math facts. Second graders should be able to skip-count, i.e., count by 5s or 10s until they get to 100. By the end of the year, a second grader should have addiction and subtraction facts memorized. Go over these simple exercises at the end of each tutoring session to hammer them home.
Touch on the previous day's lesson at the beginning of each session. Math is all about building a foundation of knowledge, so each lesson builds on what the student has already learned. Recapping previous lessons will help do this.
Use math worksheets or come up with practice problems of your own for each tutoring session. It's important to test the student each day on her knowledge of the lesson so you can see potential weaknesses and help her out.