If you sell a scarf for 100 yuan, you can earn 25%. If you sell it for 120 yuan, what percentage can you earn?
一条围巾，如果卖100元，可赚25%，如果卖120元，可赚百分之几？
<gadget id="calculator">25 / 100</gadget>
<output>1/4 = around 0.25</output>

<gadget id="calculator">1 + (1/4)</gadget>
<output>5/4 = around 1.25</output>

<gadget id="calculator">100 / (5/4)</gadget>
<output>80</output>

<gadget id="calculator">120 - 80</gadget>
<output>40</output>

<gadget id="calculator">40 / 80</gadget>
<output>1/2 = around 0.5</output>

<result>1/2 = around 0.5</result>