There are 50 peach trees, 4 fewer than the pine trees (3/5). How many pine trees are there?
桃树50棵，比松树的(3/5)少4棵．松树有多少棵？
<gadget id="calculator">4 + 50</gadget>
<output>54</output>

<gadget id="calculator">3 / 5</gadget>
<output>3/5 = around 0.6</output>

<gadget id="calculator">54 / (3/5)</gadget>
<output>90</output>

<result>90</result>