What you can observe
Repeated rounds can make the rules familiar and may shorten your completion time. You can practise staying with a small task, finding targets in clutter, and following a sequence. Those are descriptions of what you do during play, not guarantees of a lasting change outside the game.
What remains uncertain
A faster 5×5 time does not establish faster reading, expanded peripheral vision, better grades, improved driving, or treatment of an attention condition. To test transfer, researchers need an untrained outcome, a comparison group, and conditions that separate learning the game from a broader effect.
A useful way to practise
Choose a comfortable size, play a few rounds, and compare only like with like. If reading is your goal, also practise reading and measure comprehension alongside speed. Stop if your eyes feel strained; the timer is a game result, not a health target.
Sources and further reading
Try a table · Learn about Schulte tables · How to play · FAQ