Goal

Memorise as many numbers as you can in 60 seconds. Each crack scores points and eventually unlocks longer, faster numbers.

Rules

• A number appears briefly — memorise it while the bar drains. The clock pauses while it shows.
• It disappears. Use the keypad to enter what you saw; it checks itself when every slot is full.
• First wrong attempt gets a second try.
• Wrong twice on a number costs 2 seconds and moves you to the next number.
• Numbers start at 6 digits. Every 3 cracks adds one more digit (max 10).
• Every 5 cracks the display time shrinks slightly.

Scoring

3 points per digit for every number you crack — longer numbers are worth more. Crack numbers on the first try to build a streak.

Digit Span

Digit span — how many items you can hold in working memory — is one of the strongest predictors of fluid intelligence. Training it transfers to reading, maths, and multi-step problem solving.