OC Mathematical Reasoning: what is tested and how to prepare
The topics in the OC Mathematical Reasoning section and strategies for multi-step word problems without a calculator.
Updated 8 November 2026
Mathematical Reasoning has 35 questions in 40 minutes, each with five options. It rewards children who can use maths to solve unfamiliar problems.
Topics that come up often
| Area | Examples |
|---|---|
| Number | Place value, rounding, factors and multiples, mental strategies |
| Fractions and decimals | Fractions of amounts, comparing fractions, decimals and percentages |
| Patterns | Number sequences, growing patterns, missing numbers, simple equations |
| Measurement and time | Perimeter, area, volume, unit conversion, elapsed time, timetables |
| Geometry | Angles, symmetry, 2D and 3D shapes, position and direction |
| Data and chance | Reading graphs and tables, averages, likelihood |
| Money and ratio | Best buys, change, sharing in a ratio, rates |
Strategies worth teaching
- Underline what the question asks for. Many wrong options are the answer to a different step.
- Draw a quick sketch for shapes, distances and timetables.
- Work backwards for “I think of a number” problems.
- Check the options: substituting each option is a valid strategy in multiple-choice tests.
- Estimate first, then rule out options that are clearly too big or too small.
Every question on Smart Selective explains why each wrong option is wrong. Those notes show the most common mistakes, which are worth discussing with your child.
Sources
Smart Selective is independent and not affiliated with the NSW Department of Education. Found something out of date? Tell us.