Ask what else changed besides the thing being tested; that check sorts fair tests from unfair ones.
Practice test 1 is free. No card needed.
Science experiment questions ask whether a test is fair, what its results predict and what they can't prove. A child in Year 7 now sits them in Quantitative Reasoning in Year 8, in June 2027 Expected.
Checked by the SelectiveReady team on 12 October 2026 · Updated 27 October 2026 · How we check facts
Independent. Not affiliated with the Victorian Department of Education or ACER.
Someone runs a small test, and your child judges whether it was fair and what the results really show. ACER says Quantitative Reasoning tests thinking and reasoning with numbers, patterns and shapes, in abstract and real-world settings. Experiments are a real-world kind: seeds, a bouncing ball, paper towels.
In our questions no science facts are needed, because everything is in the question. These three are our own, from easier to harder, each with the answer and the working shown. For each wrong option, list together what changed between the setups, then ask which change the question was really about.
Priya wants to find out whether bean seeds sprout faster in a warm place than in a cool place. Which plan is a fair test?
Answer: A
Answer: A
In a fair test only the thing being tested changes (here, warm or cool) and everything else stays the same. Plan A does this. Plan C is tempting, but it also changes the watering, so any difference could come from the water. Plan B changes the type of seed, and Plan D has nothing to compare with.
Liam dropped the same ball onto the same floor from three different heights and measured how high it bounced. If the pattern in his results continues, how high would you expect the ball to bounce when dropped from 120 cm?
| Drop height | Bounce height |
|---|---|
| 50 cm | 35 cm |
| 100 cm | 70 cm |
| 150 cm | 105 cm |
Answer: C
Answer: C
Each bounce is 7 tenths of the drop height: 35 out of 50, 70 out of 100, 105 out of 150. For 120 cm, 7 tenths of 120 is 84 cm. Choosing 90 cm takes away 30 cm as at 100 cm, but the gap grows as the drop gets higher (15, 30, 45 cm).
Mei tested three kinds of paper towel, P, Q and R, to find out which soaks up the most water. She dipped a strip of each towel into water and measured how much water it soaked up. Which statement about Mei's test is correct?
| Towel | Strip width | Time in water | Water soaked up |
|---|---|---|---|
| P | 10 cm | 1 minute | 12 mL |
| Q | 10 cm | 2 minutes | 15 mL |
| R | 5 cm | 1 minute | 8 mL |
Answer: A
Answer: A
To compare towels fairly, only the towel should change. P and Q were dipped for different times, P and R were different widths, and Q and R differed in both, so no fair comparison is possible. C is tempting because the times match, but R's strip was half as wide, which alone could explain why it soaked up less.
Name the one thing the test is meant to change, then hunt for anything else that changed too. A test is only fair when that single thing differs, so this check sorts the options quickly. Quantitative Reasoning shares 60 minutes with Mathematics, and a quick check leaves time for the harder questions.
This is our method, not ACER's. It works for plans, results tables and claims alike.
Name the one thing the test is meant to change: warm or cool, the drop height, the kind of towel.
Watering, seed type, strip width, time in the water. Anything else that differs spoils a fair test.
Compare each result with its setting, such as 35 out of 50. Check whether the link is a fixed gap or a fixed fraction.
Options that say always, or that name a winner, need a fair test behind them. Check that the test can support the claim.
Each trap here is a thinking slip, not a science gap. For each wrong option, find its slip in this list and talk through what the test would need to change. A good check to practise: "Could anything else explain the difference?"
Small kitchen experiments build this skill, and they're fun to run together. ACER says these skills grow over time, through a culture of learning, varied engaging material and talking freely about ideas, which suits curious talk at home.
More worked questions are on our quantitative reasoning sample questions page. Three questions show the check; a full sitting shows whether your child still uses it with Mathematics on the same clock. Our selective entry practice tests keep the real timing, Practice test 1 is free, and the results by skill show whether this kind costs marks.
Practice test 1 marks every answer and shows results by skill: what your child already does well and the three skills to work on next.
Practise for the real test
Practice test 1 is free. Then packs from A$109 for 12 months, or A$9 a week, per exam.