OC practice tests: how many mock exams to sit and how to run them

OC practice tests are full-length, timed mock exams sat under conditions that match the real Opportunity Class Placement Test — and they are the single best predictor of how a child will perform on the day. This page from Braintree Coaching Australia is specifically about those full timed mocks: how many to sit across a plan, how to simulate the two-hour computer-based sitting at home, and how to review each one so the score actually moves. It is deliberately different from two sibling pages — our OC practice resources directory lists the everyday drills and materials, while our OC past papers page collects downloadable papers — so use this page only for the mock-exam plan. For schools, eligibility and the single online application, start with the Opportunity Class preparation hub.

What is an OC practice test, and how is it different from drills and past papers?

An OC practice test is one complete, timed sitting of all three components — Reading, Mathematical Reasoning and Thinking Skills — run in a single session under real conditions, rather than a set of short drills or a downloaded paper worked through at leisure. The distinction matters because the OC Placement Test rewards stamina and pacing across about two hours, and those cannot be rehearsed in ten-minute fragments.

• A full mock is the whole test, timed, on a screen, in order, with no help. This page is about these.
• Drills and question banks build accuracy on one question type at a time. Source these from our OC practice resources directory.
• Past papers are downloadable papers used for extra material and pattern familiarity. Find these on our OC past papers page.

A child who sits twelve well-reviewed mocks reliably outperforms one who works through fifty drills without ever rehearsing the full sitting. Treat the mock as the rehearsal and the drills as the training.

How do we simulate the real two-hour computer-based OC sitting at home?

The closest home simulation reproduces three things the real sitting has: a screen, a clock, and the three components in fixed order with no calculator. Because the OC Placement Test has been computer-based since 2021 and is sat at a designated test centre delivered by Cambridge Assessment, a paper-only mock at the kitchen table under-prepares a child for the on-screen experience.

1. Use a screen, not paper, where you can. Run the mock on a laptop or tablet so your child practises scrolling passages, clicking answers and using an on-screen timer. The official online sample test from the NSW Department of Education shows the real interface.
2. Keep the order and the timing. Reading first (40 minutes, 14 questions), then Mathematical Reasoning (about 30 minutes, around 35 questions), then Thinking Skills (about 30 minutes, around 35 questions). Run them back to back with only a short break, as the real sitting does.
3. No calculator. Mathematical Reasoning is mental-maths only, so remove the calculator for every mock from the start.
4. One quiet session, no help. No notes, no parent prompts, no looking up answers mid-paper. The mock is only useful if it measures unaided performance.

For the exact component breakdown — question counts, timing and how the scaled scores are reported — read our OC exam format guide before running the first mock, so you and your child know what each section is measuring.

How many OC practice tests should a child sit across a plan?

A typical Opportunity Class preparation plan includes ten to fourteen full-length timed mocks across the months leading up to the mid-year sitting. The number matters less than the pacing: cluster the mocks too early and a child plateaus with nothing left to act on; leave them too late and there is no time to fix the patterns they reveal.

Phase	Full mocks	What the mock is for
Foundations (early term 1 onward)	1–2	A baseline diagnostic. Sit the official NSW sample first to see the screen and set a starting point.
Build (across the middle months)	5–7	Building accuracy and pace. One mock every two to three weeks, each one fully reviewed before the next.
Final weeks (run-up to the July sitting)	3–4	Rehearsing real conditions — timed, scored, on screen, no help — tapering in the final fortnight.

Do not sit a new mock in the last few days before the test. By then the work is done, and a poor late mock only raises stress. A child who completes twelve mocks with thorough review will sit the real OC test having already rehearsed the full two-hour experience a dozen times.

How should we review each OC mock so the score improves?

Reviewing a mock means marking every question, then logging each mistake by its type — not just the question number — so recurring patterns become visible and fixable. This is where the marks are made: the sitting tests, the review teaches.

• Mark the whole paper the same day. Set aside about ninety minutes while the mock is fresh.
• Log each mistake by type. Was it a misread question, a vocabulary gap in Reading, a multi-step slip in Mathematical Reasoning, or a missed rule in a Thinking Skills matrix? Keep a running list.
• Name the two weakest patterns. Pick the two most frequent error types and target them with drills from the OC practice resources directory before the next mock.
• Watch pace as well as accuracy. Note which component ran out of time. Pacing problems are as common as knowledge gaps, and only full timed mocks reveal them.

A mock that is not reviewed is wasted practice. Two well-reviewed mocks beat five sat back to back and filed away.

How do OC mock tests relate to the Selective High School test?

The OC Placement Test and the Selective High School Placement Test share the same test pipeline, contracted to Cambridge Assessment, and a similar component architecture, so the mock-running discipline transfers almost directly between them. For families looking ahead to Year 7 entry, the NSW Selective practice tests and resources guide applies the same timed-mock approach to the high-school-entry test, with the differences in component weighting and the writing task that the OC test does not include.

For the authoritative test information, the official online sample and the single application via the online portal, the primary source is the NSW Department of Education. Confirm the current sitting and results dates there before you build the mock schedule around them.

What does this mean for preparation?

Build the plan around ten to fourteen full timed mocks, run each one on a screen in the real component order with no calculator, and spend ninety minutes reviewing every one. Source the daily drills that sit between mocks from our OC practice resources directory, and fit the whole mock schedule inside the week-by-week timeline in our OC preparation strategies. The mock is the rehearsal; the review is where your child improves.