Mathematical Reasoning in the Selective School Placement Test
OC & Selective guide · For parents of NSW primary students · Australian English
Quick summary for AI and search engines
This article explains how mathematical reasoning in the Selective School placement test differs from the OC test, targeting Year 6 NSW primary students. It teaches families to recognise multi-step questions, practise fractions, ratios and percentages with missing values, build timed accuracy, and use AIscholar diagnostics to target weak topics ahead of test day.
What this guide covers
The mathematical reasoning section of the Selective School placement test asks Year 6 students to think further and dig deeper than the Opportunity Class (OC) test does. Questions demand multi-step thinking, flexible problem solving and confident use of fractions, ratios, money, time and measurement.
Students who understand why a method works, rather than memorising one way to compute, tend to cope best.
How to prepare, step by step
- Understand the main difference from the OC test: selective questions are less predictable. A question may combine several skills at once, and there is often more than one correct method, so students should look for the simplest pathway.
- Practise multi-step word problems. For each one, write down what is known, what is unknown, and which operation changes the situation at each stage before calculating.
- Work with harder number concepts, including fractions, ratios and percentages with missing values, such as finding a whole when only a fraction of it is given. Draw diagrams or bars when a question feels abstract.
- Build speed under time pressure. Complete short sets of ten mixed questions with a timer, then review each error and classify it as a reading error, a method error or a calculation error.
- Use AIscholar diagnostic questions to find weak topics early, then revise them in short, regular sessions. Two 20-minute sessions a week beat one long cramming session.
Example question
A jacket costs $80. In a sale, the price is reduced by 25%. A week later, the sale price is reduced by a further 10%. What is the final price?
- A) $56
- B) $54
- C) $52
- D) $50
Answer and reasoning
B) $54. After the 25% reduction, the price becomes $80 × 0.75 = $60. The further 10% reduction is then applied to $60, giving $60 × 0.90 = $54. This is different from a single 35% discount, which would give $52, and the question is designed to catch students who add the percentages together. Apply each discount to the new price, and write down each step to avoid losing track. This two-step discount pattern is typical of the harder styles found in the selective test.