Baby Kindergarten has 120 people in the small class and 180 people in the big class. If every 30 children need a life teacher, then how many more life teachers are needed for the children in the big class than in the small class.
宝宝幼儿园小班有120人，大班有180人．如果每30名小朋友需要一名生活老师，那么大班小朋友需要派的生活老师比小班需要派的生活老师多多少名．
<gadget id="calculator">180 / 30</gadget>
<output>6</output>

<gadget id="calculator">120 / 30</gadget>
<output>4</output>

<gadget id="calculator">6 - 4</gadget>
<output>2</output>

<result>2</result>