Khet and Quarto, are games of what type?
Quarto (board game) Quarto is a board game for two players invented by Swiss mathematician Blaise Müller in 1991. It is published and copyrighted by Gigamic.
Krypto (game) Krypto is a card game designed by Daniel Yovich in 1963 and published by Parker Brothers and MPH Games Co. It is a mathematical game that promotes proficiency with basic arithmetic operations. More detailed analysis of the game can raise more complex statistical questions.