The check digit is used to confirm the initial digits of the card number. The benefits of using a checksum is that it prevents casual attempts to invent credit card numbers, as only one in ten will be valid.
Length (adj). the longest, or longer, dimension of any object, in distinction from breadth or width; extent of anything from end to end; the longest line which can be drawn through a body, parallel to its sides; as, the length of a church, or of a ship; the length of a rope or line.
THE BIGGEST ARE ABOUT 40 FEET LONG. Itâs often said that the whale sharkâs maximum length from end to end is about 45 feet, but this is a fish story. The longest verified measurements of live (or recently dead) specimens are in the 40-foot range.