What is the difference between 60 and 50% of it?
60减去它的50%，差是多少？
<gadget id="calculator">50 / 100</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">60 * (1/2)</gadget>
<output>30</output>

<gadget id="calculator">60 - 30</gadget>
<output>30</output>

<result>30</result>