Year 9 Maths in Australia: What Your Child Learns

Year 9 maths gets more powerful. Algebra expands, Pythagoras' theorem and trigonometry arrive, and students start working with non-linear relationships.

This guide explains what your child learns in Year 9 maths under the Australian Curriculum, the skills to watch for, and easy ways to help at home.

What your child learns in Year 9

Australian maths is organised into six areas. Here is what each looks like in Year 9.

Number

Applying index laws, using scientific notation, and working with the real number system, including rational and irrational numbers.

Algebra

Expanding binomial products, factorising, and working with linear and simple non-linear relationships, including simultaneous equations.

Measurement

Using Pythagoras' theorem and basic trigonometry to solve right-angled triangle problems, and finding surface area and volume.

Space

Investigating similarity, and using geometric reasoning and proof.

Statistics

Comparing data sets, working with samples, and exploring scatter plots.

Probability

Calculating relative frequencies, and working with two-step and compound events.

💡 Parent tip: Year 9 is a turning point — it shapes which senior maths your child can choose. Staying steady here keeps options open.

🖼️ Image: Graphs and statistics built from real-world data. *(Replace this line with your uploaded image.)*

What is new compared to Year 8

Real-life maths in Year 9

• Trigonometry for heights, ramps and distances.
• Scientific notation for very large and very small numbers.
• Scatter plots showing real-world correlations.
• Surface area and volume in design and packaging.

Skills to look for by the end of Year 9

By the end of the year, most students can:

• Apply index laws and use scientific notation
• Expand and factorise expressions
• Use Pythagoras' theorem and basic trigonometry
• Interpret scatter plots
• Calculate relative frequency
• Solve simple simultaneous equations

Where Year 9 students often struggle

• Trigonometry — knowing which ratio (sin, cos or tan) to use.
• Negative and fractional indices.
• The workload step-up and keeping multi-step working tidy.

💡 Parent tip: Year 9 results matter for senior subject choices. If your child is struggling, this is the year to get support — not Year 11.

How you can help at home

• Encourage steady, short daily practice.
• Use worked examples to model clear steps.
• Talk through real trigonometry — ladders, ramps, roofs.
• Use online practice for fast feedback.

Try a few Year 9 questions

1. Expand (x + 3)(x + 2).
2. A right-angled triangle has shorter sides 3 and 4 — what is the hypotenuse?
3. Write 45,000 in scientific notation.
4. Simplify x⁵ × x³.

🎯 Want more? Your child can try 10 free Year 9 questions — multiple choice, with instant feedback.

Free Year 9 maths worksheets

Printable, curriculum-aligned worksheets for Year 9 topics — algebra, trigonometry, indices and more — each with an answer key. Browse and download free Year 9 maths worksheets here.

Does this change by state?

Year 9 maths is broadly the same nationwide. In NSW it sits in Stage 5 with a Core–Paths structure — the "Paths" are optional extension topics — but the core content matches the national curriculum.

Keep going

• ← Year 8 maths guide
• → Year 10 maths guide
• 📘 The complete Australian maths curriculum guide

Year 9 is the year that opens or closes senior maths options. Keep it steady and well supported.