Teacher: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.
Teacher: Now, understand the problem? Solve this instance: the map led them through the forest and into a cave . to open the cave doors they need to put weights on the switch . if the switch already has 234 lbs . of weights and the total needed is 712 lbs . how much more weight to they need to add ?
Student:
478