This is the final topic in the series of lessons on math provided by DeafTEC. Gary Blatto-Vallee, a math and science instructor at the National Technical Institute for the Deaf, guides viewers through a variety of mathematical exercises in this DeafTEC video series. All lessons are fully captioned, signed in ASL, and voiced. In this final section, three series of videos teach students the graphing method, substitution method, and addition method for solving systems of equations. After each series of videos, problems are included for students to check their understanding. See the main Math Video Resources page for an introduction to this video series.