A is 10, after increasing by 50%, then decreasing by 50%, what is the result
甲是10，增加50%后，再减少50%，结果是多少
<gadget id="calculator">50 / 100</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">1 + (1/2)</gadget>
<output>3/2 = around 1.5</output>

<gadget id="calculator">1 - (1/2)</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">10 * (3/2) * (1/2)</gadget>
<output>15/2 = around 7.5</output>

<result>15/2 = around 7.5</result>