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: David did 51 push-ups in gym class today. David did 49 more push-ups than Zachary. 

 Question: How many push-ups did Zachary and David do altogether?
53

Context: Danny collects bottle caps. He found 36 bottle caps at the park while he threw away 35 old ones. Now he has 22 bottle caps in his collection. 

 Question: How many more bottle caps did danny find at the park than those he threw away?
1

Context: Winter is almost here and most animals are migrating to warmer countries. There were 89 bird families living near the mountain. If 60 bird families flew away for winter 

 Question: How many more bird families flew away for the winter than those that stayed behind?

31