What we are going to do is first to convert the mixed number to a fraction and then convert 6.5 into a fraction too, then we will divide the wide of the room by the length of each table, to know how many tables fits in the classroom:
and
then
Since Mr. Martin can't cut the tables, we need to aproximate the number to 3
then the answer is that Mr. Martin can fit 3 tables across the width of the classroom.