This text provides information and exercises on arithmetic topics which should be mastered before a student enrolls in an Elementary Algebra course. Section I describes the fundamental properties and relationships of whole numbers, focusing on basic operations, divisibility tests, exponents, order of operations, prime numbers, greatest common divisors, and least common multiples. Section II covers the addition, subtraction, multiplication, and division of integers, i.e., signed whole numbers. After Section III establishes the fundamental properties of fractions, it deals with performing basic operations with fractions and with proportions and complex fractions. Decimals are examined in Section IV, which covers decimal notation, basic operations with decimals, square roots, and percents. Section V looks at the use of integers as exponents and explains scientific notation. The last section presents rudiments of algebra, including like terms, multiplication and division of monomials, and literal formulas. In addition to interspersing reinforcement exercises throughout the explanatory text, each section concludes with a set of review problems. Concluding the text are answer keys for all of the exercises and review problems, a pretest to aid counselors and math faculty in assessing a student's basic arithmetic background, and an index. (AYC)