Memorize the positions of numbers, then tap them in order.
Numbers 1 to N appear at random positions on a 5×5 grid.
Tap "1" first — the rest are then hidden. Tap them in order from memory.
Clearing a round grows N by 1. Three mistakes ends the game.
Goal: reach the highest N you can.
This game is famously based on a study where young chimpanzees outperformed humans at exactly this task, because they memorise spatial layout in a single glance instead of reading the numbers one by one. Copy that approach: do not recite "one, two, three", instead photograph the whole grid as a shape and remember where the cluster sits, not what the digits say.
The board hides after you tap 1, so spend your looking time on the positions of the higher numbers, which are the ones you are most likely to forget. Group them into a path your finger can trace — top-left, then dip to the middle, then the corner. Three mistakes ends the run, so when you are unsure of one number, tap the cells you are certain about first to lock in those points before gambling on the doubtful one.