The school held a book donation activity. Sixth Class 1 donated 290 books, and Sixth Class 2 donated 350 books. The books donated by these two classes in Grade Six accounted for 1/4 of the total number of books donated by the school. How many books were donated by the whole school?
学校举行捐书活动，六1班捐了290本，六2班捐了350本，六年级这两个班捐的书占全校捐书总数的(1/4)，全校共捐书多少本？
<gadget id="calculator">290 + 350</gadget>
<output>640</output>

<gadget id="calculator">1 / 4</gadget>
<output>1/4 = around 0.25</output>

<gadget id="calculator">640 / (1/4)</gadget>
<output>2_560</output>

<result>2_560</result>