After the price of a watch has been reduced by 10% twice in a row, it sells for 40.5 yuan. How much was it originally sold for?
一种手表连续两次降价10%以后，售40.5元，原来售多少元？
<gadget id="calculator">10 / 100</gadget>
<output>1/10 = around 0.1</output>

<gadget id="calculator">1 - (1/10)</gadget>
<output>9/10 = around 0.9</output>

<gadget id="calculator">40.5 / (9/10) / (9/10)</gadget>
<output>50</output>

<result>50</result>