Credit card numbers follow certain patterns. A credit card must have between 13 and 16 digits. It must start with: â¢ 4 for Visa cards. â¢ 5 for Master cards. â¢ 37 for American Express cards. In 1954, Hans Luhn of IBM proposed an algorithm for validating credit card numbers. The algorithm is useful to determine if a card number is entered correctly or if a credit card is scanned correctly by a scanner.
The phrases used for discounted items include,  off, Save 50%, and Get a 20% discount.. Procedure: 1  To calculate the discount, multiply the rate by the original price. 2  To calculate the sale price, subtract the discount from original price.
The discount of $3,851 is treated as an additional interest expense over the life of the bonds. When the same amount of bond discount is recorded each year, it is referred to as straight-line amortization. In this example, the straight-line amortization would be $770.20 ($3,851 divided by the 5-year life of the bond).