Students of Hongxing Elementary School watered the small trees. The fifth grade watered 356 trees, 72 more than the fourth grade. How many trees are watered in the fourth grade? (List the solution to the equation involving the unknown x.)
红星小学学生给小树浇水．五年级浇了356棵，比四年级多浇了72棵．四年级浇多少棵？(列含有未知数x的等式解答．)
<gadget id="calculator">356 - 72</gadget>
<output>284</output>

<result>284</result>