instruction:
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.
question:
Context: David did 40 more push-ups but 17 less crunches than Zachary in gym class today. If Zachary did 34 push-ups and 62 crunches

Question: How many crunches did David do?
answer:
45

question:
Context: Edward had $ 13. He spent some money. Now he has $ 3.

Question: How much money did Edward spend?
answer:
10

question:
Context: A book has 2 chapters across 81 pages. The second chapter is 68 pages long.

Question: How many pages are in the second chapter?
answer:
13