Quinto (grid game)
Quinto is an addictive grid "numbers" game, with play that resembles Scrabble, except the tiles are numbers rather than letters. The vertical and horizontal total must always be a multiple of five, and five is the maximum tiles that can be in a contiguous run. Play alternates between two players. The score of each play, as in Scrabble, is the sum of all numerical totals of each vertical or horizontal run created by the play. Each play can be horizontal or vertical, but not both.
The original board game began to be sold beginning in the 1950's by 3M, and is no longer being manufactured. As of 2020, a lively online trade exists in old, used Quinto tile games.
There is also an older card game named Quinto available through online trade; it has little resemblance to the tile game.
In 2018, programmer J. R. Heard created an online version of Quinto written in Javascript, so that it executes locally in your web browser. It was written using some very modern tools, and details about the code are also online. Heard provided a smart computer component that is virtually unbeatable by humans, and also play hints that help a human increase their skills.