There are 40 peach trees in the park, and the number of willow trees is 10 times that of peach trees. How many willow trees are there?
公园有40棵桃树，柳树的棵树是桃树的10倍，柳树有多少棵？
<gadget id="calculator">40 * 10</gadget>
<output>400</output>

<result>400</result>