H.S. Math is a term used to refer to the mathematics courses taught in high school. The two most common courses are Algebra and Trigonometry, which are abbreviated as ALG and TRIG respectively. ALG stands for Algebra, which is a branch of mathematics that deals with symbols and the rules for manipulating those symbols. TRIG stands for Trigonometry, which is a branch of mathematics that deals with the relationships between angles and sides of triangles.