Another, more competitive way is to write a problem on the board. It can be a question relating to anything that has been taught this school year. Students write their answer on a slip of paper, put their name on it, and put it in a hat. When a piece of paper is drawn, the person whose name is on the paper is only eligible if they answered the question correctly. (Eligibility requirements have been met. More closely mimics the rules of the game show.) 

Examples of questions I've used are putting words in ABC order (primary grades), putting numerical values in order which may include decimals or fractions depending on grade level of students, matching famous people with their accomplishments, and so on.