Number Sequence Memory
Memorize and recall growing sequences of numbers.
Play now →Number Mirror
Memorize the number, then type what a mirror would show — the digits reversed. Every round the number grows and the clock shrinks. How far can you flip?
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Completed
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Best
Press Start
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Type the number you would see in a mirror — reversed!
How to play
- Press Start — a number appears with a draining timer bar.
- Type its mirror image: the same digits in reverse order.
- Submit with the Enter button — or press Enter on your keyboard; both work the same.
- Correct answers add a digit and cut the time limit.
- A wrong answer or a timeout ends the run.
Frequently asked questions
How does Number Mirror work?
A number flashes on screen — 527, say. Type what you would see in a mirror: 725. That is, reverse the digit order. Correct answers add digits and shave time off the clock; one mistake or a timeout ends the run.
What is a good score?
Three to five numbers is a solid start. Nine or more means you are reversing eight-digit strings under a three-second clock — genuinely elite working-memory territory.
What does this actually train?
Visuospatial working memory plus mental manipulation — holding a string in mind while transforming it. It is the same machinery you use reading maps, doing mental arithmetic with carries, or following a chess line.
Is it the same as saying the digits backwards?
Saying digits backwards is a pure auditory-span task. Here the mirror metaphor matters: you must treat the number as a spatial object and flip it, which recruits visual-spatial processing on top of memory.
Any tips for longer numbers?
Chunk the string into pairs (52|71 → 17|25 reversed), or visualize the digits written on a card and literally flip the card in your mind. Reading right-to-left from the start beats reversing at the end.