Found this program which is the free version of DJ Pre-Algebra. It comes with only chapter 1 with 30 problems. Chapter one only covers the basics of adding and subtracting signed numbers. The student is given a problem such as E = 1 + 5 and the student chooses the number of bubbles with the letter E that corresponds with the correct answer. This is not something I would use with my high school students. I might consider using it for a much younger group of students who are just starting out with signed numbers. The problems are a bit too easy and there is no activity as a reward to make them want to strive towards something. I think that having a number line on the side to help students see how signed numbers work might make it easier for students to really learn the material. I would guess that this is good for 5th or 6th grade.