I was thirsty today and I brought (3/4) bottle of water and drank (1/4) bottle at noon. How many bottles of water are left.
今天口渴我带了(3/4)瓶水，中午喝了(1/4)瓶．还剩下多少瓶水．
<gadget id="calculator">3 / 4</gadget>
<output>3/4 = around 0.75</output>

<gadget id="calculator">1 / 4</gadget>
<output>1/4 = around 0.25</output>

<gadget id="calculator">(3/4) - (1/4)</gadget>
<output>1/2 = around 0.5</output>

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