The current cost is 10% lower than the original one. What is the current cost?
现在的成本比原来降低了10%，现在的成本是原来的多少
<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>

<result>9/10 = around 0.9</result>