A peanut milk factory delivers 4500 cases of new milk to supermarkets every day. Today, 20 trucks have been shipped, and each truck has shipped 165 boxes. How many boxes are left undelivered?
某花生牛奶厂每天向超市运送4500箱新牛奶．今天已经运送了20车，每车运165箱，还有多少箱没有运送？
<gadget id="calculator">165 * 20</gadget>
<output>3_300</output>

<gadget id="calculator">4_500 - 3_300</gadget>
<output>1_200</output>

<result>1_200</result>