Due to the negligence of the supermarket staff, the weight of one of the five bags of rice was mistaken for 30 kg, so the average weight of each bag was calculated as 60 kg, but the actual average weight of each bag should be 70 kg. The wrong bag of rice How many kilograms does it weigh.
超市工作人员由于工作疏忽，把5包大米中1包的重量错看成30千克，因而算得每包的平均重量为60千克，实际每包的平均重量应为70千克，看错的这包米重多少千克．
<gadget id="calculator">70 * 5</gadget>
<output>350</output>

<gadget id="calculator">60 * 5</gadget>
<output>300</output>

<gadget id="calculator">300 - 30</gadget>
<output>270</output>

<gadget id="calculator">350 - 270</gadget>
<output>80</output>

<result>80</result>