The fourth and fifth graders went to the exhibition together. There were 300 students in the fifth grade, 20 more than twice the number in the fourth grade. How many people went to the fifth and fourth grades?
四五年级同学一起去参加展览，五年级有300人，比四年级的2倍还多20人．五年级和四年级一共去了多少人？
<gadget id="calculator">300 - 20</gadget>
<output>280</output>

<gadget id="calculator">280 / 2</gadget>
<output>140</output>

<gadget id="calculator">140 + 300</gadget>
<output>440</output>

<result>440</result>