The fourth and fifth grade students participate in the group gymnastics competition held by the school. There are 4 classes in the fourth grade, with 40 students in each class; there are 4 classes in the fifth grade, with 36 students in each class. How many people in grades 4 and 5 participated in the competition? ．
四、五年级同学参加学校举行的团体操比赛，四年级有4个班，每班选40人；五年级有4个班，每班选36人．四、五年级共有多少人参加比赛？．
<gadget id="calculator">40 * 4</gadget>
<output>160</output>

<gadget id="calculator">36 * 4</gadget>
<output>144</output>

<gadget id="calculator">160 + 144</gadget>
<output>304</output>

<result>304</result>