The four classes of the third grade held the activity of "I contribute to environmental protection". On the first day, 36 plastic bags were picked up, 41 plastic bags were picked up on the second day, and 43 plastic bags were picked up on the third day. How many plastic bags are picked up per shift on average?
三年级四个班举行"我为环保作贡献"的活动，第一天捡回塑料袋36个，第二天捡回塑料袋41个，第三天捡回塑料袋43个．平均每班捡回塑料袋多少个？
<gadget id="calculator">36 + 41 + 43</gadget>
<output>120</output>

<gadget id="calculator">120 / 4</gadget>
<output>30</output>

<result>30</result>