The sixth grade of Yucai Attached Primary School has 302 students, 95 more than the fifth grade, and the fifth grade has 23 more students than the fourth grade. How many students are there in the fourth, fifth and sixth grades of Yucai Attached Primary School?
育才附小六年级有学生302个，比五年级多95人，五年级又比四年级多23人．育才附小四五六年级一共有多少人．
<gadget id="calculator">302 - 95</gadget>
<output>207</output>

<gadget id="calculator">302 - 95 - 23</gadget>
<output>184</output>

<gadget id="calculator">302 + 207 + 184</gadget>
<output>693</output>

<result>693</result>