GAME 1: TOTS OY! ( A Child's First Math Game )
Remove the higher numbers and replace them as players become more proficient. Play to win the most cards. All cards are dealt to the players, who hold them face down in a stack. OY! cards are wild. The first player plays the top card from their stack to the table face up. Each player in turn plays one card on top of the previous player's card. If the new card is higher in value than the previous card, or if an OY! card is played, whoever first calls OY! wins all the played cards and places them at the bottom of their stack, then plays the next card. A player who calls OY! incorrectly, must play three penalty cards one at a time. If any of these cards are higher than the previous card, any player can call OY! and win the cards.
Variations: Require that the winning number must be lower in value than the previous number or the next card has to be at least 2 numbers higher or lower to call OY!. Then it must be at least 3 higher or lower and so on.

GAME 2: LINE OY! (Easy, Slow; Suitable for Solitaire)
Each player is dealt 6 cards which are held face up in their hands. A LINE of five cards is placed face up on the table. Each player in turn plays 1 or 2 cards on top of the selected LINE cards to form a combination of 3 cards where 2 cards added or subtracted equal a third. Players receive and record points based on the number of each card used including the LINE card/s, then replenish their hands to 6 cards from the Stock Pile. Played cards are left on the LINE. The OY! card can represent any number, but has no value. A player unable to make a combination discards one card to a Discard Pile, replaces it with a new card from the Stock Pile, and misses that turn. When the Stock Pile is depleted, players count their scores to select the winner.
Variations: To play solitaire, play as above but without scoring until you have used all the cards in the Stock Pile. You may also play against time by trying to make the most combinations in a preset period. Consider using multiplication and division.
Tips: To increase the challenge, deal more cards to each player, increase the number of cards in the line and require combinations of at least 4 or more cards.

GAME 3: SET OY! ( A Slow Game )
Play to get rid of all your cards. Assign the OY! cards a value. Each player takes 7 cards and the remaining cards are placed in a Stock Pile. In turn, players take one card from the Stock Pile and attempt to make a set of two or three cards which when added and/or subtracted equal the target number, which starts at zero and increases by 1 number after every player has had one turn, until the highest card number is reached and then starts again at zero. The player shows their set and places it on the discard pile. If a set cannot be made, the player calls pass and the next player plays. The game ends when a player has laid out all their cards.
Variations: Use three or four card sets, multiplication and division, and increase the target number past 16. When no Stock Cards remain, the Discard Pile is made into a new Stock Pile.

GAME 4: QUAD OY! ( Play slow or fast, even solitaire )
Play to win the most cards. Assign the OY! card a value. The dealer (who also plays) turns a Target Card face up from the Stock Pile and deals 4 cards to the first player who uses addition and/or subtraction of as many of the four cards as they can to equal the Target Number. The player then places the Target Card and Solution cards in their win pile. Any cards not used in the solution are passed on to the next player who receives an additional 4 cards and a new target number. If a player is unable to find a solution the next player receives those 4 cards and 4 new cards and a new target card (placed on top of the old target card). Play until there are no more Stock Cards.
Variations: Consider using multiple target numbers as shown under variations 1 and 2 in HIGH 5 OY!. Allocate a turn time limit for skilled players for fast and very dramatic play. This is best achieved using the G8 Game Timer.