After drinking (1/2) of a bottle of soda, and then drinking the rest (1/2), how much soda is left in the bottle
一瓶汽水喝了(1/2)后，又喝了余下的(1/2)，这时瓶中的汽水还剩多少
<gadget id="calculator">1 / 2</gadget>
<output>1/2 = around 0.5</output>

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

<gadget id="calculator">1 * (1/2) * (1/2)</gadget>
<output>1/4 = around 0.25</output>

<result>1/4 = around 0.25</result>