After 100 kg is increased by 50%, how much is it to decrease by 50%.
100千克增加50%后，再减少50%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">100 * (3/2) * (1/2)</gadget>
<output>75</output>

<result>75</result>