The math topics covered in eighth grade are determined, with some degree of variation, by the individual school district. In general, eighth grade math covers the topics of algebra and geometry with an emphasis on word problems and the introduction of mathematical formulas. Practice questions can be found online by searching for "free eighth grade practice worksheets."
Concepts covered in eighth grade math are dimensions, the spatial relationships between geometric figures, symmetry, ratios, percentages, graphing, Venn diagrams, balancing equations, prime numbers, factoring, exponents, radicals, monomials, polynomials, absolute value and logarithms. Eighth grade algebra primarily deals with the latter. Geometry is the study of size, shape, figures and the properties of space. Eighth grade geometry usually only gives an introduction to shape and equations to solve for shape-related questions. This could include ideas such as area, circumference, perimeter and radius.
In essence, eighth grade math is the introduction to new mathematical concepts, and it aims to transition students from working concretely with the four basic processes (addition, subtraction, multiplication and division) to using them in a more abstract manner. In addition, eighth grade algebra familiarizes students with solving equations for a variable and graphing a word problem with bar graphs or diagrams.