Subtraction Tic-Tac-Toe
Players choose markers in two different colors. The first player chooses two numbers
from beneath the game board, places a paper clip on each, and marks the difference
with his/her color marker. The second player moves one of the paper clips to a new
number, finds the difference, and marks that difference with his/her color marker.
Play continues until one player has marked four numbers in a row, a column, or a
diagonal. Note: it is legal to move the paper clip to the same number of the other
paper clip to allow for doubles such as 5 - 5.
0 6 4 8 9
2 1 9 5 7
7 0 2 3 8
5 3 1 6 4
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18
One-to-One Math