Is It Time For A Cell-Phone Free Classroom? By now all teachers know how ubiquitous cellphones are in the classroom. 90% of college age adults have cellphones, according to research, and in my experience at Allan Hancock College I would have to say that number is closer to 100%. It seems every student has a cellphone, and many just can’t seem to stop using them even in situations where they know and you know it is inappropriate (such as in the...