This publication contains a sequence of lectures given to high school mathematics teachers by the author. Applications of mathematics emphasized are elementary algebra, geometry, and matrix algebra. Included are: (1) an introduction concerning teaching applications of mathematics; (2) Chapter 1: Mechanics for the High School Student; (3) Chapter 2: Growth Functions; (4) Chapter 3: The Role of Mathematics in Optics; (5) Chapter 4: Application of Matrix Algebra. Included in each chapter are background materials, examples, some teaching suggestions, and some exercises. (RH)