There is an orange tree on the top of the mountain. A monkey ate the oranges. On the first day, it ate (1/10), on the second day it ate (1/9) from the tree of the day,... on the ninth day, it ate the tree of the day (1/2) on the tree, eat up all 9 oranges on the tree on the tenth day. How many oranges were there on the tree?
山顶有棵桔子树，一只猴子偷吃桔子，第一天偷吃了(1/10)，第二天偷吃了当天树上的(1/9)，…第九天偷吃了当天树上的(1/2)，第十天将树上的9个桔子全部吃光．问树上原有多少个桔子？
<gadget id="calculator">10 / 2</gadget>
<output>5</output>

<gadget id="calculator">18 * 5</gadget>
<output>90</output>

<result>90</result>