The purchase form printed out after swiping the card will have a field for your card number. The complete card number should not be displayed on it. Several digits will be hidden with * instead. It was lost, but the first and last digits of the card number are there. You can check whether it is a savings card number or a credit card number. There are also 19 digits for debit cards and 16 digits for credit cards. You can roughly judge from the length of the card number.