At the science and technology festival held at Xinghu Primary School in Zhaoqing City, students of all grades exhibited their science and technology works. There are 32 pieces of scientific and technological works that are not in the third grade, and 24 are not in the fourth grade. It is known that there are 30 pieces in the third and fourth grades, so how many pieces are there in the fourth grade?
在肇庆市星湖小学举行的科技节上，各年级学生均有科技作品展．科技作品中有32件不是三年级的，有24件不是四年级的，已知三、四年级有30件，那么四年级有作品多少件．
<gadget id="calculator">32 - 24</gadget>
<output>8</output>

<gadget id="calculator">8 + 30</gadget>
<output>38</output>

<gadget id="calculator">38 / 2</gadget>
<output>19</output>

<result>19</result>