Jeopardy for PowerPoint uses Visual Basic Macros (VBA) to help keep score between the various contestants. Just click on "Incorrect" and the value will be subtracted from that player's score, or "Correct" and the value will be added and then the answer slide will be shown. Click the "Adj Scores" button to manually edit scores, or click the "Reset" button to reset the board and scores.
You can also use an Excel spreadsheet to automatically import your prompts and responses. Just fill out the question template in Excel and then click the "Import from Excel Template" button on the instructions page and select your Excel document. The macro will fill in all the details.