Be mindful that students are not rushing through the work and sacrificing quality for speed. Monitor work during the activity closely and set expectations for quality at the beginning of the lesson.
Try rewarding positive behaviors during countdowns by acknowledging students. For example, “5, 4….John is ready…3, 2….Allison is ready…1.”
Consider using countdowns to set goals for the class. “I know we did this by my count of 8 last time, this time let’s go for 6.”