This is an excellent review game I used in many of co-ops. There are many variations to this game that you can use.
Print baseball graphic, you are able to size the ball to fit your needs. Write the review questions on the baseball graphic using four different levels:
Singles = not difficult
Double = somewhat difficult
Triples = difficult
Home Run = very difficult
Divide the class into two teams.
Flip a coin to see who goes first.
The "batter" gets to choose which level of question he wants. Each player gets only one question (chance) at bat, not three as in the real game.
If someone from same team calls out the answer, it is considered a "strike" and the batter gets a new question.
If someone from the other team calls out the answer, it is considered a "walk" and the batter gets to move to first base.
If the batter answers the question correctly, he advances according to difficulty of question.
If the batter answers incorrectly, it is an "out".
Three outs signifies the end of an inning and the next team is up to bat.
The team with most runs at the end of nine innings whens the game!