9th grade Math: how to help at home
What your child learns in 9th grade math in the California Content Standards, and simple things to try at home.
Focus areas this year
- Algebra I: expressions, equations and inequalities, including absolute value
- Functions: linear, exponential and quadratic functions and their graphs
- Statistics: describing data, two-way tables and scatter plots
Easy ways to practice math at home
- Look for fractions, decimals and percentages in sale signs, sports statistics and recipes.
- Ask your child to explain a problem to you as if you were the student.
- Estimate first (the bill, the trip time), then check with a calculator.
- Keep a tricky-problems list and revisit it every few days instead of re-doing everything.
What each unit covers
Exponents & Powers
Evaluating powers, using the product, quotient and power laws, working with powers of products and fractions, and order of operations with exponents.
Polynomials
Naming polynomials by terms and degree, combining like terms, subtracting polynomials, multiplying and dividing by a constant, and substituting values for x.
Multi-Step Equations
Solving linear equations with brackets, fractions and variables on both sides, checking solutions, and turning word problems into equations.
Linear Relations
Finding slope from points and graphs, reading y = mx + b, finding intercepts, deciding whether a point is on a line, spotting parallel lines, and using rates of change in stories.
Statistics in Society
Telling a population from a sample, spotting bias in who is asked and how, predicting from a sample, noticing misleading graphs, and why correlation is not causation.
Number Sets
Natural numbers, whole numbers, integers, rational and irrational numbers, how they fit inside each other, and why there are always more numbers between any two rational numbers.
Expressions
Writing an expression for a pattern or a sentence, deciding which expressions are equivalent, expanding brackets, and collecting like terms.
Lines & Intersections
Finding where two lines meet and what it means in a story, graphing x = k, y = k and ax + by = k, regions of an inequality, and translating, reflecting and rotating lines through the origin.
Data & Scatter Plots
Finding the median and quartiles of a data set, reading a box plot, telling positive, negative and no correlation apart, and using a line of best fit to make predictions. Correlation does not prove one thing causes another.
Function Notation
Evaluating and solving with function notation, and naming the domain and range of a function, including a sensible domain in a real situation.
Linear Inequalities
Solving linear inequalities (flipping the sign when dividing by a negative), checking a solution, and writing inequalities from budgets and limits.
Solving Systems
Solving systems of two linear equations by elimination and substitution, and writing a system from a word problem.
Linear or Exponential?
Telling linear growth (add the same amount) from exponential growth (multiply by the same factor), writing exponential functions, and reading growth and decay rates.
Factoring & Quadratics
Factoring quadratic expressions (common factors, trinomials, difference of squares) and solving quadratic equations by factoring and square roots.
Rearranging Formulas
Rearranging a formula to solve for one quantity (d = rt for t, P = 2l + 2w for l) and using it, plus justifying each step in solving an equation.
Two-Way Tables & Causation
Reading two-way frequency tables, finding conditional relative frequencies, spotting associations, and knowing that correlation does not prove causation.
Sequences
Arithmetic and geometric sequences as functions: finding any term, writing a rule, and using a recursive rule.
Absolute Value Equations
Solving one-variable equations and inequalities with absolute value, reading |x − a| as the distance from a, and writing absolute-value inequalities for real tolerances. Absolute value equations are a California addition to Algebra I.
What the report card levels look like at home
- Beginning
- Just getting started with this idea. Short, regular practice with lots of support helps most.
- Approaching
- Understands parts of it and is building confidence. Keep practicing the tricky parts.
- Meeting
- Has it! Mixed review now and then keeps it strong.
- Exceeding
- Applies it confidently, even in new or harder situations. Try challenge mode and real-life problems.
Your child’s teacher decides the level on the report card. Read the California report card guide.
Common questions
Look for fractions, decimals and percentages in sale signs, sports statistics and recipes. Ask your child to explain a problem to you as if you were the student. Keep sessions short, about 10 to 15 minutes, and stop on a success.
The California Content Standards 9th grade math units include Exponents & Powers, Polynomials, Multi-Step Equations, Linear Relations, Statistics in Society, Number Sets.
Free printable 9th grade math practice sheet
Questions from every unit, with an answer key.