A schoolbag is priced at 45 yuan after a 10% discount. How much is the original price?
一个书包，打9折后售价45元，原价多少元．
<gadget id="calculator">90 / 100</gadget>
<output>9/10 = around 0.9</output>

<gadget id="calculator">45 / (9/10)</gadget>
<output>50</output>

<result>50</result>