This math workbook, authored by Chris McMullen, Ph.D., is focused on essential prealgebra skills. It includes examples, plenty of practice problems, answers, and full solutions to most problems. Topics include: order of operations; PEMDAS; fractions, decimals, and percents; exponents and square roots; a beginning introduction to working with variables; ratios and rates; negative numbers; and other prealgebra skills. The author, Chris McMullen, Ph.D., has over twenty years of experience teaching math skills to physics students. He prepared this workbook of the Improve Your Math Fluency series to share his strategies for applying arithmetic and prealgebra skills.