I have. Who has. Is a fun way to get the entire class involved with mental math. To begin playing, each student is dealt a card. One student starts by reading the "I have" statement at the top of their card followed by the "Who has" question. All students study their cards and the student who has the correct answer on the top of their card responds by reading their I have followed by the"Who has" question. This continues until the sequence returns to the first player. Record the amount of time it takes the class to complete the activity and challenge the class to complete the activity in less time.