For a bag of rice, if 3/4 of it is used, how much less is the rest than what was used?
一袋大米，用去了它的(3/4)，剩下的比用去的少几分之几？
<gadget id="calculator">3 / 4</gadget>
<output>3/4 = around 0.75</output>

<gadget id="calculator">1 - (3/4)</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>