I’ve always taught in schools that use a block schedule. The shortest blocks being 80 minutes and the longest ones being 240 minutes! Therefore, I’ve always used some type of timer to keep track of how long students were working on an activity and to keep track of break times between activities. When I first started teaching I did that with an actual egg timer like this one. Later I started using online countdown timer tools. The first one being Online-Stopwatch.com. That’s one of the four convenient classroom timers that I featured in this short video.