Key to Percents emphasizes mental computation and estimation skills since most work with percents is done without pencil and paper. Afterwards, students are taught to solve percent problems using equal fractions, decimal multiplication and word problems in a variety of applications. Key to Percents assumes only knowledge of fraction and decimal computation. 45 pages, paperback.
Book 3 covers percents and decimals, including simplification and figuring out how to write a number as a percent, fraction and decimal number.