There are 150 peach trees in the orchard, and the number of pear trees is four times that of peach trees. How many fewer peach trees are there than pear trees?
果园里有桃树150棵，梨树的棵数是桃树的4倍，桃树比梨树少多少棵？
<gadget id="calculator">150 * 4</gadget>
<output>600</output>

<gadget id="calculator">600 - 150</gadget>
<output>450</output>

<result>450</result>