This is the 620th most frequent Russian word.
втором
"Втором" means "second" (prepositional case, masculine/neuter singular).
Here, "втором" is the locative form of the ordinal numeral "второй" used to specify 'in the second grade'.
Во втором классе ученики начинают изучать иностранный язык.
In the second grade, students begin to learn a foreign language.
Here, "втором" is used in the prepositional case to denote the location of the mistake within the second paragraph.
Она нашла ошибку во втором абзаце текста.
She found a mistake in the second paragraph of the text.
In this sentence, "втором" specifies that the chips belong to the individual who is the second player, with the prepositional case indicating the possessive.