For this game, separate the students into groups (and have them choose a team name). You can give each group a whiteboard/marker. You can either keep track of their points on the blackboard or you can have them keep track of their own points on their whiteboard. Have the students switch who is writing/answering each time a question is asked.
Janken to see which order the groups will go in. When it's their turn, have them choose a category and dollar value (just like regular jeopardy). Have them use the whiteboards to answer if you're using them. If they answer the question correctly, add the dollar value to their points. If they answer incorrectly, then subtract the dollar value. Then, have the next group pick a category and dollar value (repeat process until questions are finished). Highest dollar value at the end of the game wins.