Detailed Instructions: You are given a math word problem and you are supposed to apply a single mathematical operator like addition, subtraction, multiplication, or division on the numbers embedded in the text to answer the following question and then only report the final numerical answer.
Problem:for the walls of the house he would use 9 large planks of wood . if each plank of wood needs 8 pieces of nails to be secured how many nails does john need for the house wall ?
Solution:
72