There are 45 apple trees in the orchard of Grandpa Wang’s house, and the number of peach trees is 20 times that of apple trees. How many peach trees does Grandpa Wang’s house have?
王爷爷家的果园有苹果树45棵，桃树的棵树是苹果树的20倍，王爷爷家有桃树多少棵．
<gadget id="calculator">45 * 20</gadget>
<output>900</output>

<result>900</result>