The fifth grade students held a book donation activity and donated 586 books. 50 books were packed into a pack, and 11 packs were packed. How many books are left?
五年级同学举行捐书活动，捐了586本书，50本包成一包，包了11包，还剩几本书？
<gadget id="calculator">50 * 11</gadget>
<output>550</output>

<gadget id="calculator">586 - 550</gadget>
<output>36</output>

<result>36</result>