Ages 13–16 · Grades 7–10
Secondary Maths (Ages 13–16)
Secondary maths is where algebra takes centre stage. Letters stand in for numbers, equations are solved systematically, and graphs connect algebra to geometry. Probability and statistics become more formal, and money maths becomes directly useful.
These lessons are written to support classroom learning and exam revision. Every page shows the full working, not just the answer.
By the end of this stage
- Simplify expressions, expand brackets and factorise
- Solve linear equations and quadratic equations by more than one method
- Plot and interpret straight-line graphs using
- Apply Pythagoras' theorem and circle formulas
- Calculate probabilities of single and combined events
- Work out simple and compound interest
Lessons for this level
Numbers
Algebra
- Algebraic Expressionsx
- Substitution into Expressionsx
- Collecting Like Termsx
- Expanding Single Bracketsx
- Factorising with a Common Factorx
- Solving Equationsx
- Writing Equations from Word Problemsx
- Inequalities and Number Linesx
- Coordinates in Four Quadrantsx
- Linear Equationsx
- Using and Rearranging Simple Formulasx
- Functions and Graphsx
- Quadratic Equationsx
Geometry
Data & Statistics
Measurement
Try this
Phone plan showdown
- Plan A costs $10 a month plus $0.05 per text. Plan B costs $18 a month with unlimited texts.
- Write a formula for the monthly cost of each plan, using for the number of texts.
- Set the formulas equal and solve to find the break-even number of texts.
- Decide which plan suits someone who sends 100 texts a month, and someone who sends 300.