The school held a sports meeting, with 70 participants in the fifth grade and 52 participants in the fourth grade. The number of participants in the fifth grade was twice that of the third grade. How many people in the three grades participated in the sports meeting?
学校举行体育运动会，五年级有70人参加，四年级有52人参加，五年级参加的人数是三年级的2倍．三个年级一共有多少人参加体育运动会？
<gadget id="calculator">70 / 2</gadget>
<output>35</output>

<gadget id="calculator">35 + 52 + 70</gadget>
<output>157</output>

<result>157</result>