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 average length of your standard school bus is around 45 feet long. So according to this comic a Colossal Squid is 90 feet long. I mentioned in my other post about the sizes of Giant Squids that the longest recorded specimen was 42 feet long, 3 feet shy of a single school bus. Now here is the kicker. Giant Squids are longer than Colossal Squids.