El Quim told the class that paper comes from trees, which surprised them. They want to investigate how trees can be transformed into paper. After researching on YouTube, they learned that paper is made from cellulose extracted from tree trunks. It then goes through different machines. They realized many things are made of paper and weighed their paper bin, finding they use about 2kg of paper per week. Making 100 sheets of recycled paper uses less resources than new paper. They then made their own recycled blue paper.