Time doesn't have to be an illusion with a 15 Minute Classroom Sand Timer. Quite the opposite, in fact. A Sand Timer for classrooms provides pupils with a visual and practical representation of time - a very helpful resource for pupils developing their concrete understanding as part of a Maths Mastery approach. Make teaching time a breeze with a concrete representation of 15 minutes with a Classroom Sand Timer. Support problem solving skills and cooperative work in groups by using a school Sand Timer to time group tasks. Use as a calming tool or time out resource.