A professor divided the students into several groups, gave each group some puzzle pieces, and timed them to see which group could be completed first. In fact, numbers were marked on the back of each puzzle piece in order. Only by splicing them in the order of these numbers, the whole picture can be spelled out quickly. However, few groups noticed this, and some found that there were number marks on the back after a long time, Some didn't see it at all.
passage intended to explain?
Careful observation is more conducive to success