There are 865 students in the third, fourth, and fifth grades. The third grade has 2 more students than the fourth grade, and the fourth grade has 7 more students than the fifth grade. How many students are there in the fourth grade?
三、四、五三个年级共有学生865人，三年级比四年级多2人，四年级比五年级多7人，四年级有多少人．
<gadget id="calculator">7 + 2</gadget>
<output>9</output>

<gadget id="calculator">865 - 7 - 9</gadget>
<output>849</output>

<gadget id="calculator">849 / 3</gadget>
<output>283</output>

<gadget id="calculator">283 + 7</gadget>
<output>290</output>

<result>290</result>