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.

Context: Jerry had some action figures on a shelf in his room. Later he added 7 more action figures to the shelf. If there are a total of 10 action figures on his shelf now 

 Question: How many action figures did he have initially on the shelf?
3

Context: Zachary did 44 push-ups and 17 crunches in gym class today. David did 29 more push-ups but 13 less crunches than zachary. 

 Question: How many crunches did David do?
4

Context: A waiter had 8 customers. After some left he still had 5 customers. Then he got 99 new customers 

 Question: How many customers left?

3