- Player X and Player O each select one of the numbers, 0 – 12 at the bottom of the page and places one of the markers on that addend.
- Player X may move only one of the two addend markers to a different addend. Player X then places a marker on the grid covering the sum of the two addends.
- Player O may move only one addend marker at the bottom of the page, 0 – 12. Player O makes a new sum and covers it on the grid. The markers can be placed on the same numbers, 0 – 12. For example, two markers on 12 would be 12 + 12 = 24 and the player would cover 24 on the grid.
- Players alternate moving one addend marker at a time and continue placing their markers until a player has marked four sums in a row. After the game players should discuss their strategies.
- Two markers for the bottom row of addends (for example, paper clips)
- Two sets of different markers for each player to cover each sum (for example, pennies and nickels)
- Tic-Tac-Toe Sums Game Sheet
From Helping with Math at Home: More Ideas for Parents. 2006. Portsmouth, NH: Heinemann.