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

[Q]: Ned had to wash 9 short sleeve shirts and 21 long sleeve shirts before school . If he had only washed 29 of them by the time school started , how many did he not wash ?
[A]: 1

[Q]: Joan has 9 blue balloons , Sally has 5 blue balloons , and Jessica has 2 blue balloons . How many blue balloons do they have in total ?
[A]: 16

[Q]: Mike is at the library helping put away books . There are 82 book to put away total but a librarian takes 10 of them and leaves Mike with the rest . If he can fit 9 books on a shelf , how many shelves will he need ?
[A]:
8