I believe they carry, almost all books and their class notes, home work notes and all sundry. For a class VII student, last time I checked it was around 22 pieces. I talked to principal and she says that it is the parents who are to be blamed. As per her they(school) wanted to reduce homework etc. until class V to zero. Students need not have to carry their home work notes etc. to class and home(homework notes and workbooks constitute around 60 percent) which will be deposited with the corresponding subject teacher and he/she will manage those. After implementing this rule the parents started complaining how their children are going to loose out to competition without the workload that other schools are providing. So the school committee decided to dilute the implementation of that rule.
