Each player controls 4 cars that race forward on 4 tracks formed by track tiles with different numerical values which are randomly laid out during setup. In order to move their cars, players play a number tile from their hand of 4 number tiles onto the tableau on the table to create sums (in rows or columns) which permit moving cars onto tracks with that exact value. E.g. playing a number card which creates a row 4+3+1 permits a player to advance all of his cars which would move onto a track tile with value 8. The game has an easy variant (3x3 tableau of number cards & lower values on track tiles) and hard variant (tableau which grows without bound, like Scrabble or Qwirkle & higher values on track tiles).
As soon as some player's car reaches the end of a track, no further movement occurs in that track. The game ends when all tracks are completed, and the winner is determined by summing the progress of each player's cars on all 4 tracks.