The fifth grade donated 597 books, 50 books were packed into a pack, and 11 packs were packed, how many books are left?
五年级捐了597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">597 - 550</gadget>
<output>47</output>

<result>47</result>