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

A teacher had 6 worksheets to grade . If she graded 4 , but then another 18 were turned in , how many worksheets would she have to grade ?
20

Bridget has 4 Skittles . Henry has 4 Skittles . If Henry gives all of his Skittles to Bridget , how many Skittles will Bridget have ?
8

Mike picked 8 pears and Jason picked 7 pears from the pear tree . Fred picked 6 apples from the apple tree . How many pears were picked in total ?
15