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.

[EX Q]: While taking inventory at her pastry shop , Kelly realizes that she had 0.4 box of baking powder yesterday , but the supply is now down to 0.3 box . How much more baking powder did Kelly have yesterday ?
[EX A]: 0.1

[EX Q]: Maria has 3 boxes of eggs . Each box holds 7 eggs and there are 8 boxes in a case . How many eggs does Maria have ?
[EX A]: 21

[EX Q]: Sara had 21 quarters in her bank . Her dad gave her 49 quarters . How many quarters does she have now ?
[EX A]:
70