🔢 9th grade Math: how to help at home

What each unit covers

1. 🔢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.

2. 🚀Exponents & Powers

   Evaluating powers, using the product, quotient and power laws, working with powers of products and fractions, and order of operations with exponents.

3. ⚖️Multi-Step Equations

   Solving linear equations with brackets, fractions and variables on both sides, checking solutions, and turning word problems into equations.

4. 🔧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.

5. ⚖️Linear Inequalities

   Solving linear inequalities (flipping the sign when dividing by a negative), checking a solution, and writing inequalities from budgets and limits.

6. 📈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.

7. 🔣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.

8. 📉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.

9. 🔗Solving Systems

   Solving systems of two linear equations by elimination and substitution, and writing a system from a word problem.

10. 🔢Sequences

    Arithmetic and geometric sequences as functions: finding any term, writing a rule, and using a recursive rule.

11. 🚀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.

12. 🔭Similarity & Scale

    Using scale factors to find missing sides, solving shadow and scale-drawing problems, and seeing how enlarging a shape changes its area and volume.

13. 📐Right Triangles & Scaling

    Using the Pythagorean relationship for ladders, ramps, roofs and diagonals, deciding whether a triangle is right-angled, and seeing how doubling or tripling dimensions changes perimeter, area and volume.

14. 📦Surface Area of Objects

    Finding the surface area of a rectangular prism, of two solids joined together (taking away the faces that are hidden), and of a cylinder written in terms of π.

15. 📊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.

16. 📊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.

17. 🧮Two-Way Tables & Causation

    Reading two-way frequency tables, finding conditional relative frequencies, spotting associations, and knowing that correlation does not prove causation.

18. 📐Right-Triangle Trig

    The three trig ratios in a right triangle (SOH CAH TOA), choosing the right ratio for the sides you know, finding a missing side, and seeing why sin A = cos B for the two acute angles.

19. 🧭Coordinate Geometry

    Finding the distance between two points with the Pythagorean Theorem, the midpoint of a segment, slopes of segments, telling parallel and perpendicular lines apart, and using slopes to check for a right angle.