This set of 20 modules was designed for use primarily to help teach and reinforce the basic mathematics skills in electronics classes. The modules are based on electronics competencies that require mathematics skills, as determined by a panel of high school electronics and mathematics teachers. Each module consists of one or two pages of basic information, including a brief discussion of the electronics concepts involved, formulas, and examples showing how the formulas are used. Following the information sheet(s) are several sheets of problems for the students to work; solutions are included. Also included with the modules is a "teach sheet" of basic mathematics rules, and a module on metrics. Topics covered by the modules are the following: mathematics rules, broadcast frequency, calculating cost of power, calculating power, circuit value, decibels, frequency, horsepower, impedance, instantaneous sine voltage, metrics, Ohm's Law, Op-amplifiers, reactance, rectification, resistance (parallel), resistance (series), transformer ratios, voltage, and wavelength. (KC)