This is the 9665th most frequent Russian word.
чеком
The Russian word "чеком" is the instrumental case of "чек," meaning "by check" or "with a check" (a financial document).
In this sentence, 'чеком' is used as the instrumental case of the noun 'чек', which means 'check or cheque'. It is showing the method of payment, which is typical for the instrumental case usage in Russian.
Я оплатил покупки чеком.
I paid for the purchases with a check.
Here, the word 'чек' in its nominative form refers to a receipt from a transaction, which is another common meaning of the term in Russian.
Он показал мне чек после оплаты.
He showed me the receipt after the payment.
In this example, 'чек' also means 'check' in the sense of a written payment order, which is understood from the context of the action of signing it.