The primary objective in the design of Mathematics for Machine Technology is to present those mathematical concepts and practical application of concepts that are generally required by skilled employees in the machine trades and related occupations. Presentation of concepts and their solutions is immediately followed by realistic industry-related applications. The applications progress from the simple to those whose solutions are relatively complex. The contents of this text range from general arithmetic processes to complex right and oblique triangle applications, compoundangle problems, and computer numerical control. An understanding of mathematical concepts through realistic trade applications is stressed in all topics presented. Many students have a tendency to forget a concept if it is not used frequently. To help students retain an idea, most sets of exercises begin with six “Tooling Up” exercises that use concepts from earlier units. These “Tooling Up” exercises are in each unit except for Unit 1 and the nine Achievement Review units at the end of each section. Throughout the text, the student is required to work with illustrations, tables, and charts such as those found in machine trade handbooks and on engineering drawings. Student activities are similar to those actually required on the job. In Section I—Common Fractions and Decimal Fractions, general arithmetic processes are presented with many practical applications. Section 2—Ratio, Proportion, and Percentage, is next presented in order to provide a unified approach to teaching percent and to lay a foundation for unit conversion and unit analysis. Following these first two sections, both customary and metric units of measure are presented in the topics, examples, and problems. Upon completion of the text, students should be equally familiar and proficient with both systems of measure as they relate to machine trade applications. An ample number of customary and metric problems are given. Content may be selected and problems assigned based on the degree of emphasis to be placed on each system. The scientific calculator is introduced in the Preface. Further instruction and examples are given throughout the text wherever calculator applications are appropriate to the material presented. Calculator information and sequencing in examples and practical applications have been updated and expanded in this editon. The use of the calculator is left as an option to the instructor. Naturally, students may be permitted to solve problems using calculators at the discretion of the instructor. The individual instructor is best able to identify student needs and the computational skills developed with his/her unique group of students. Section 3—Linear Measurement: Customary (English) and Metric was developed to enable students to use customary and metric units with equal facility when computing tolerances, clearances, and interferences. A unit was added on metric calipers and height gages and a unit was added on metric micrometers. Because electronic, digital instruments are replacing hand-read/analog instruments, two units were added to acquaint student with using electronic, digital instruments. One unit was added on digital calipers and height gages and a unit was added on digital micrometers. The content in Section 4—Fundamentals of Algebra was selected and developed to provide the learner an adequate base for working with handbook formulas and for subsequent computations required in practical geometry and trigonometry applied problems. The algebra concepts presented are those actually needed for the vast majority of situations encountered on the job. Therefore, concepts such as types of factoring, complex fractional equations, systems of equations, and quadratic equations were purposely excluded from the