Too many students end their study of mathematics before ever taking an algebra course. Others attempt to study algebra, but are unprepared and cannot keep up. "Key to Algebra" was developed with the belief that anyone can learn basic algebra if the subject is presented in a friendly, non-threatening manner. Some teachers find that their students benefit by working through these books before enrolling in a regular algebra course, others as a basic text for an individualized class, while others use it as a supplement. This series of informal books are self-directing, and students should be allowed to work at their own pace. Book 3 covers Equations (solving, equivalent, finger method, addition principle, age puzzles, perimeter problems, division principle and multiplication principle.)37 pages, paperback.