Teacher Zhang distributed fruit to the children in the two classes of the kindergarten. Each person in the big class was given 2 apples and 5 oranges, and each person in the small class was given 2 apples and 3 oranges. Teacher Zhang gave out a total of 80 apples and 158 oranges. ． Question: How many children are there in the small class?
张老师给幼儿园两个班的孩子分水果，大班每人分2个苹果和5个桔子，小班每人分得2个苹果和3个桔子，张老师一共分出了80个苹果和158个桔子．请问：小班有多少个孩子？
<gadget id="calculator">80 / 2</gadget>
<output>40</output>

<gadget id="calculator">40 * 5</gadget>
<output>200</output>

<gadget id="calculator">200 - 158</gadget>
<output>42</output>

<gadget id="calculator">5 - 3</gadget>
<output>2</output>

<gadget id="calculator">42 / 2</gadget>
<output>21</output>

<result>21</result>