Count the Moving Objects
White balls bounce around inside a black circle. Work out how many there are and pick that number from the row of buttons — as quickly and accurately as you can, for as many rounds as the clock allows.
Each round the balls drift into place and pause for about a second, then start moving.
Five close numbers are offered, e.g. 9 10 11 12 13.
How this practice works
- Adaptive: a right answer makes the next round harder (more balls, faster); a wrong one makes it easier. There are 12 levels.
- You are told straight away whether each answer was right.
- Practice first: 3 slowed rounds, untimed, with the balls numbered afterwards so you can check.
- Then the timed run: 60 seconds. The clock keeps running while you look, so don't get stuck on one round.
- If you switch tabs the clock stops and that round is discarded.
Controls
Tap or click the number. On a keyboard, keys 1–5 choose the buttons from left to right (the small grey number on each button).
About the real test
Prep providers list Aon's scales cmo (monitoring ability, about 2 minutes) among the online tests in NATS Stage 1. Aon describes it as counting moving objects, with each test built by an item generator. Candidate reports describe balls bouncing inside a circle, close answer options, instant right/wrong feedback and difficulty that adapts. NATS does not publish the test names, so treat this as practice modelled on that format, not a copy of it.
Your assessment
Don't go in unprepared.
Aptitude tests reward familiarity: knowing the format and pace of each test before the day lets you spend your attention on the questions themselves.
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