If you sell a pair of leather shoes for 140 yuan, you can earn 40%; if you sell it for 120 yuan, how much can you earn?
一双皮鞋若卖140元，可赚40%；若卖120元，可赚多少
<gadget id="calculator">40 / 100</gadget>
<output>2/5 = around 0.4</output>

<gadget id="calculator">1 + (2/5)</gadget>
<output>7/5 = around 1.4</output>

<gadget id="calculator">140 / (7/5)</gadget>
<output>100</output>

<gadget id="calculator">120 - 100</gadget>
<output>20</output>

<gadget id="calculator">20 / 100</gadget>
<output>1/5 = around 0.2</output>

<result>1/5 = around 0.2</result>