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.
Whilst she currently holds the record for the smallest waist on a living person, the record for the smallest waist ever goes to Ethel Granger who had a wasit of just 13. Russian woman Svetlana Pankratova has, according to Guinness World Records, the longest legs of any woman in the world. While she is not the world's tallest woman, her legs are 132 centimetres (4 ft 4 in) long. Because her upper body is of much more typical dimensions, she is 196 centimetres (6 ft 5 in) tall.