“I have…Who has…?” is a fun game series designed to get the entire class involved with mental math. One student starts by reading the “I have” statement at the top of his/her card followed by the “Who has” question. All students study their cards and the student who has the correct answer on the top of his/her card responds by reading his/her “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.