Usage patterns
〈場所〉に硬貨を入れるto insert a coin (into a vending machine, slot, etc.)
I inserted a coin into the vending machine.
硬貨で払うto pay in coins
I decided to pay with coins.
硬貨を数えるto count coins
I counted the coins and put them in a bag.
硬貨が足りないto not have enough coins
I don't have enough coins for the vending machine.