Lexin Kindergarten bought 278 balloons. After each class divided into 38 balloons, there were 12 balloons left. How many classes are there in this kindergarten?
乐心幼儿园买来278只气球，每个班级分38个后，还剩12个．这个幼儿园有多少个班级？
<gadget id="calculator">278 - 12</gadget>
<output>266</output>

<gadget id="calculator">266 / 38</gadget>
<output>7</output>

<result>7</result>