A product is sold at 30% off and bought for 140 yuan, how much is this product cheaper than the original price?
一件商品打七折出售后买了140元，那么这件商品比原价便宜了多少钱？
<gadget id="calculator">70 / 100</gadget>
<output>7/10 = around 0.7</output>

<gadget id="calculator">140 / (7/10)</gadget>
<output>200</output>

<gadget id="calculator">200 - 140</gadget>
<output>60</output>

<result>60</result>