Yuhua Garment Factory will make 8,500 down jackets to support the disaster area. It has been done for 11 days, with an average of 300 pieces per day, and the rest of the plan is completed in 13 days. How many more pieces will be made per day on average? (column comprehensive formula calculation)
豫华服装厂要做8500件羽绒服支援灾区．已经做了11天，平均每天做300件，其余的计划13天完成，平均每天要比原来多做多少件？(列综合算式计算)
<gadget id="calculator">11 * 300</gadget>
<output>3_300</output>

<gadget id="calculator">8_500 - 3_300</gadget>
<output>5_200</output>

<gadget id="calculator">5_200 / 13</gadget>
<output>400</output>

<gadget id="calculator">400 - 300</gadget>
<output>100</output>

<result>100</result>