TASK DEFINITION: You are given a math word problem and you are supposed to only use subtraction on the numbers embedded in the text to answer the following question and then only report the final numerical answer.
PROBLEM: Context: A waiter had 3 customers. After some more arrived he had 8 customers.

Question: How many new customers arrived?

SOLUTION: 5

PROBLEM: Context: Carol was sending out birthday invitations to her friends. Each package of invitations she bought had 3 invitations in it and she bought 2 packs. If she wants to invite 9 friends

Question: How many extra invitations will she need to buy?

SOLUTION: 3

PROBLEM: Context: A waiter had 3 customers. After some left he still had 4 customers.

Question: How many more customers stayed behind than those that left?

SOLUTION:
5