A book is 7 yuan. There are 47 students in the first class of the fourth grade and 53 students in the second class. How much does it cost to buy a book for each person?
一本书7元，四年级一班有47人，二班有53人，每人买一本，要多少元钱？
<gadget id="calculator">47 + 53</gadget>
<output>100</output>

<gadget id="calculator">100 * 7</gadget>
<output>700</output>

<result>700</result>