As 37 pupils will make birthday cards for the teacher 'Matsui Sensei' in the classroom meeting, it has been decided that everyone will make cards. Then,they have to make some small cards (in the shape of a rectangle 15 cm long and 10 cm wide) from some bigger rectangular sheet (45 cm long and 35 cm wide).The problem will be, "How many small cards can you make from the bigger one?