There are 200 apple trees in the orchard, and the number of apple trees is 20% less than that of pear trees. How many pear trees are there?
果园里有苹果树200棵，苹果树的棵树比梨树少20%，梨树有多少棵？
<gadget id="calculator">20 / 100</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">1 - (1/5)</gadget>
<output>4/5 = around 0.8</output>

<gadget id="calculator">200 / (4/5)</gadget>
<output>250</output>

<result>250</result>