bottle of Coke is 6.5 yuan, how much yuan will be saved compared to the original price if you buy it after a 10% discount.
一瓶可乐6.5元，打9折后买比原价省多少元．
<gadget id="calculator">90 / 100</gadget>
<output>9/10 = around 0.9</output>

<gadget id="calculator">1 - (9/10)</gadget>
<output>1/10 = around 0.1</output>

<gadget id="calculator">6.5 * (1/10)</gadget>
<output>0.65</output>

<result>0.65</result>