The original price of a bicycle is 490 yuan, but now it is sold at the original price (6/7), how much is the discount?
一辆自行车原价490元，现在按原价的(6/7)出售，优惠了多少元？
<gadget id="calculator">6 / 7</gadget>
<output>6/7 = around 0.857143</output>

<gadget id="calculator">490 * (6/7)</gadget>
<output>420</output>

<gadget id="calculator">490 - 420</gadget>
<output>70</output>

<result>70</result>