You are given a math word problem and you are supposed to apply an addition mathematical operator on the numbers embedded in the text to answer the following question and then only report the final numerical answer.

Context: Jack received 4 emails and sent 2 letters in the morning. He then received 6 emails and sent 8 letters in the afternoon. 

 Question: How many emails did Jack send in the day?
10

Context: Jack received 4 emails in the morning, 5 emails in the afternoon and 8 emails in the evening. 

 Question: How many emails did Jack receive in the afternoon and evening?
13

Context: A waiter had some customers. After 9 customers left he still had 12 customers. 

 Question: How many customers did he have at the start?

21