 If the first player has no legal moves (such as having only two-digit numbers on the rack), he or she may exchange tiles or pass, and play moves to the left.Each played tile is the solution to an arithmetic equation containing two adjacent tiles, such that a line of three numbers is formed.For example, a sequence of an 8 and a 2 on the board may have either a 4 (division), 6 (subtraction), 10 (addition), or 16 (multiplication) played next to it.