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

Mike found 6 seashells and 4 starfish , but 4 of the seashells were broken . How many unbroken seashells did Mike find ?
2

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

Mary has 9 yellow marbles . Joan has 3 yellow marbles . How many yellow marbles do they have in all ?

12