International Standard Music Number 3 left to right. These weighted digits are added together. The check digit is the integer between 0 and 9 that makes the sum a multiple of 10. For instance, for the item with ISMN beginning 979-0-060-11561: As 85 mod 10 = 5, the check digit is 10 - 5 = 5 and the full number is 979-0-060-11561-5. For another example, Robert Fripp's collection of Guitar Craft scores has the ISMN 979-0-9016791-7-7. Given first 12 digits 979-0-9016791-7, the ISMN algorithm evaluates which implies that the check digit is indeed 7 (because 123+7=130=13x10). International Standard Music Number The International Standard Music
Opposite Day Opposite Day "'Opposite Day" Opposite Day is sometimes declared retroactively to indicate that something which has just been said now has the opposite of its original meaning (similar to the practice of crossed fingers to automatically nullify promises). The game has also been compared to a children's "philosophy course." Opposite day causes a self referential paradox. On opposite day, it could be said that "Today is opposite day." Therefore, it is not opposite day, but if you say it is a normal day it would be considered a normal day, which contradicts the fact that it has previously been stated