The school holds an autumn sports meeting. There are 30 students in the second grade. The number of students in the third grade is twice that of the second grade. The number of students in the fourth grade is 27 more than that of the third grade. How many students in the fourth grade participated in this sports meeting ?
学校举行秋季运动会，二年级有30名学生参加，三年级参加的人数是二年级参加人数的2倍，四年级参加的人数比三年级多27人，四年级有多少名学生参加了本次运动会？
<gadget id="calculator">30 * 2</gadget>
<output>60</output>

<gadget id="calculator">60 + 27</gadget>
<output>87</output>

<result>87</result>