Grade 8 Math Curriculum in North America: What Children Learn

Grade 8 is the last year of the K–8 arc and the runway to high school algebra. The work gets noticeably more abstract: linear equations in two variables, functions as a concept, and the Pythagorean theorem. Children who leave Grade 8 confident are set up well for Algebra 1. Children who leave with gaps tend to struggle through high school math.

The number system

• Understanding rational and irrational numbers.
• Approximating irrationals like the square root of 2 or pi.
• Integer exponents and properties.
• Scientific notation.

Expressions and equations

• Solving linear equations in one variable, including those with variables on both sides.
• Solving systems of two linear equations in two variables.
• Understanding slope as the rate of change of a linear function.
• Graphing linear equations.

Functions

• Understanding a function as a rule assigning one output to each input.
• Comparing functions represented in different ways (equation, graph, table, words).
• Distinguishing linear from non-linear functions.

Geometry

• Rigid transformations: reflections, rotations, translations.
• Congruence and similarity through transformations.
• The Pythagorean theorem and its converse.
• Volume of cones, cylinders, and spheres.

Statistics

• Interpreting scatter plots and patterns of association.
• Lines of best fit and linear models.
• Two-way frequency tables.

Getting ready for high school

The two skills that matter most for Algebra 1 success are: solving linear equations without stumbling, and being comfortable working with negative numbers. Those are the things to practice hardest in Grade 8. Everything else in high school math is more learnable when those two are automatic.