Here is a great game for refreshing your memory of fractions (ahem... mom and dad) or learning how to simplify fractions.
This would also be great to use in class. Break students into even numbered groups or pairs.
You will need a sheet of paper divided horizontally in half with a line. The top being the numerator and the bottom, the denominator. You will also need a deck of cards per team.
Divide the deck of cards evenly. This game is very similar to the card game "War".
Each player will flip a card from the top of the deck simultaneously. One player will lay their card in the numerator and one in the denominator. Players then work to simplify the fraction. The player to first successfully get the answer correct wins the cards. If the fraction can't be simplified, players take the other players card.
The winner of the game is the player or team who successfully collects all the cards.
For younger students, you could use the game to help strengthen student's knowledge of multiplication, addition and subtraction.