The students went to the zoo, 25 people visited the Panda House, 30 people visited the Elephant House, and 18 people visited both houses. 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，两个馆都参观的有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>