I think that nowsaday the book are really heavy. My son bad was heavy when he was in pri 1. I was like wtf, as if he was in pri 1. Now in pri 2 we are all used to it. But was heartbroken at 1st that he was complaining too heavy to carry and his classroom was not in the 1st floor. We thought to get him the trolley type, but climb stair still go back the same and even heavier.