Algebra: algebraic expressions, factorization factors, inequalities and equations, including linear equations with one variable, linear equations with two variables and quadratic equations with one variable.
Geometry: triangle, including congruent triangles and similar triangles; Quadrilateral, including parallelogram, rectangle, diamond, square and trapezoid.
Preliminary statistics: data collection and arrangement, tolerance, variance, etc.
Function: There are three major functions in junior high school: linear function, quadratic function and inverse proportional function. Of course, there is a simplified trigonometric function to learn in high school: acute trigonometric function.