The students went to the zoo. There were 25 people who visited the Panda House, 30 people who visited the Elephant House, and 18 people who went to both halls. How many people went to the zoo?
同学们到动物园游玩，参观熊猫馆的有25人，参观大象馆的有30人，两个馆都参加的有18人，去动物园的一共有多少人？
<gadget id="calculator">30 - 18</gadget>
<output>12</output>

<gadget id="calculator">25 + 12</gadget>
<output>37</output>

<result>37</result>