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 longest known bootlace worm was studied in 1864 and was found to be 180 feet (55 meters) in length. Officially, this worm was declared as the longest animal in the world. This page was last modified on June 30, 2016.