Mancala

Ô Ăn Quan (literally: "Mandarin Square Capturing"), also known as Ô Láng ("Village Squares"), is a mancala game played by Vietnamese girls usually seven to ten years old. According to Ngô Quý Sơn, the oldest western source on the game, it was once played by boys too. The game is valuable for promoting calculating abilities. It is said that the Vietnamese mathematician Mạc Hiển Tích discovered số ẩn (negative numbers; literally: "hidden / secret number") in 1086 by playing Ô Ăn Quan.

The game was first described in a western language (French) by Ngô Quý Sơn in 1944. It seems to be identical to Ô Lang described by Lynn Rohrbough in 1955. A Vietnamese mancala game was also mentioned in Viltis ("Hope") in 1984 (January-February issue), a magazine of folklore and folk dance published in Denver, USA.

There is a Vietnamese mancala board in the Musée du Quai Branly (Paris, France) called pan u ao, which comes from the Muong people in Hoa Binh in northern Vietnam and was collected in 1938. Perhaps it was used for Ô Ăn Quan. The game itself seems to be related to mancala games found in Yunnan, China, such as Laomuzhu and Ceelkoqyuqkoqiji.