This is the 16180th most frequent Polish word.
umieszczając
"Placing" or "putting."
The word 'umieszczając' is used here as a gerund that describes the action of 'placing' during another action in a dependent clause.
Umieszczając książki na półce, tworzył estetyczny porządek.
Placing the books on the shelf, he created an aesthetic order.
In this use, 'umieszczając' emphasizes the ongoing action of placing figurines contributing to the main action of playing.
Dziecko bawiło się, umieszczając figurki na stole.
The child was playing by placing figurines on the table.
'Umieszczając' functions as a way to explain the method involving 'placing' which supports the main activity of learning a language.