pile of goods has (3/4) tons, if (1/3) of it is removed, how many tons are left.
一堆货物有(3/4)吨，运走了它的(1/3)，还剩下多少吨．
<gadget id="calculator">3 / 4</gadget>
<output>3/4 = around 0.75</output>

<gadget id="calculator">1 / 3</gadget>
<output>1/3 = around 0.333333</output>

<gadget id="calculator">1 - (1/3)</gadget>
<output>2/3 = around 0.666667</output>

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

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