Reel in addition and subtraction practice with this two-player variation of Go Fish! The object of the game is to create a larger numeral than your opponent by taking digits from him. Begin by having each partner secretly write a six-digit numeral with no repeating digits on a sheet of paper, such as 926,184. Instruct Player A to ask Player B for a digit. For example, he might say, “Do you have an 8?” If Player B has an 8 in his six-digit numeral, have him announce its place value (80). Then have Player A add that value to his six-digit numeral and Player B subtract it from his numeral (see the example). If Player B does not have the digit, he says, “Go fish!” and Player A scores a zero for that round. After round one, if the same number appears more than once in a player’s numeral, he may choose which place value to give away. The player with the larger numeral at the end of six rounds is the winner.
(From – The Mailbox)