How Numbubbles works
Each round gives you a target number and a set of bubbles, each holding an equation. You pop the bubbles whose equation equals the target, as quickly and accurately as you can. There are 10 rounds, each harder than the last, with just under 3 minutes for the whole game. Calculators are not allowed.
The details of each round are randomised, so no two candidates get the same sums, but the difficulty at each stage is the same for everyone. The game shows how you are doing as you play. It is scored on how quickly you respond as well as on whether each pop was right, and it is the game behind the Numerical Reasoning sub-score in the standard report.
How to play Numbubbles
You are checking sums, not solving them. Stop working on a bubble the moment you can rule it in or out:
- Fix the target in your head before you read a single bubble.
- Check the last digit first. 7 × 8 ends in 6, so it cannot be 54, and an odd result can never hit an even target.
- Check the size next. 19 × 4 is close to 80, so it is no use when the target is 52.
- Where a bubble mixes operations, multiply and divide before you add and subtract: 2 + 3 × 4 is 14, not 20.
- Make your times tables up to 12 × 12 instant. Most of the work is there.
Worked example
The target is 24, and six bubbles show 6 × 4, 30 − 7, 48 ÷ 2, 15 + 8, 3 × 9 and 12 + 12.
Last digits clear three at a glance: 30 − 7 and 15 + 8 both end in 3, and 3 × 9 is odd, so none of them can be 24. The other three all make 24 (6 × 4, 48 ÷ 2 and 12 + 12), so you pop those and leave the rest.
Tips for the real Numbubbles
- Play the tutorial until the controls are automatic. The game moves fast once the clock starts.
- Accuracy and speed both count, so do not pop a bubble you have not checked.
- Warm up with ten minutes of mental arithmetic before you start.
- Sit somewhere quiet. Three minutes of quick sums leaves no time to recover from a distraction.
- On a laptop or desktop, use a mouse rather than a trackpad.
Practise Numbubbles on CogniPrep
Our Numbubbles has 8 rounds on a 5-minute clock, with 12 bubbles a round, 3 to 5 of them matching the target. Bubbles appear a few at a time and never move, and each has its own hidden timer: it shakes about a second before it bursts, and a matching bubble that bursts counts as a miss. Sums get longer and targets can go negative as the rounds go on. Your score out of 100 is half the matches you popped, about a third the share of your pops that were right, and the rest speed. The real game packs 10 rounds into less time, so expect it to feel faster.