迷宮蟻巣 (Meikyū Arisu) (メイキュウアリス) (Labyrinth Ant Nest) is a Japanese game designed to help children with simple arithmetic.
Players are constructing an ant's nest by laying tiles to connect tunnels under the soil. Each tile has a number of paths, and each branch has a number from 1 to 9.
The players put a starting tile on the edge and a central tile in the middle of the next. Each player draws a tile and tries to place it such that paths join.
Players are trying to place tiles so that the connecting numbers add up to 10. If a player can do this, they say "Thank you! 2+8=10" (or whatever the sum is). But if a player cannot make a connection add to 10, they are not penalised.
The winner is the first player to connect their starting tile on the outside of the board to the central tile.
The designers suggest an alternate for children who cannot add up, so that they need only have numbers match when played.
Alternately, they suggest you play the game in a terrible windstorm.