Light that turns on when a student really understands

Name :
Makoto Goto
COUNTRY :
Japan / Aomori
AGE :
10
YEAR :
2012
PRIZE :
The Asahi Shogakusei Shimbun Prize
COMMENTARY :
During a lesson in arithmatics or some other subject, this light bulb put on a student's head lights up if that student really understands what the teacher is saying and feels confident. This will keep the teacher from moving on in the lesson if there are still students who don't understand, a help for the teacher.
Light that turns on when a student really understands