When I was in grade 9 Our next division science teacher put our whole class in front of our principal room because the our whole class was making noise in our free period which disturb that science teacher to take class for her students. So she put all us in front of principal room and our principal made all of us to stood in front of her room for the half day while keeping our mouth shut by putting our finger over our mouth. It was unforgettable punishment in my school days.