During this activity, students will be shown a time in numbers. They will be given 18 seconds (or however much time you think they will need) to write the time in Spanish. Each time the timer rings, they will pass their paper to the student that you assign. They will get a new sheet of paper each time.
If students are in rows, it may be easiest to have them pass their papers to the next person in the row. If they are in groups, you could have them pass the papers one person to the right or left each time as long as they are always passing to the same person.