According to the Common Core standards, eighth-grade mathematics classes should include formulating and solving linear equations, using functions to describe quantitative relationships, and covering basic geometry concepts such as distance, angles and the Pythagorean theorem. Eighth-grade mathematical concepts provide the basis for the conceptual modeling that allows students to use math to solve everyday problems.
In eighth-grade mathematics classes, students learn to use advanced arithmetic concepts such as radicals, exponents and irrational numbers. They should also begin to learn to model proportional relationships between numbers, expressing those relationships as functions.
Students learn how to solve linear equations to determine the value of a single variable, as well as linear equation systems, such as finding the values of two variables as described by a pair of linear equations. Students also learn to formulate these equations, learning to determine unknown values based on relationships.
Some of the most obvious applications of these algebra concepts come in the relationships found in the geometry concepts that students usually learn in eighth grade. Students learn to measure distance and angles, using these concepts to model two-dimensional and three-dimensional objects. Students learn to use equations that describe the relationships between angles and distances, including the Pythagorean theorem, to find the value of unknown variables.