The RightStart Mathematics Level A Lessons: Second Edition, published by Activities for Learning, Inc., is a study guide designed for elementary and high school students. Written by Joan A. Cotter, this trade paperback book in English focuses on building a foundation in mathematics through number sense and visualization strategies using the Cotter Abacus. This second edition includes lessons on addition and subtraction to 10, place value to the hundreds, geometry, and measurement. Card games and problem solving are also incorporated into the curriculum, making it an engaging and educational resource for students in the United States.