A pile of cement (3/5) tons, transport away (2/3), how many tons are left.
一堆水泥(3/5)吨，运走(2/3)，还剩多少吨．
<gadget id="calculator">3 / 5</gadget>
<output>3/5 = around 0.6</output>

<gadget id="calculator">2 / 3</gadget>
<output>2/3 = around 0.666667</output>

<gadget id="calculator">1 - (2/3)</gadget>
<output>1/3 = around 0.333333</output>

<gadget id="calculator">(3/5) * (1/3)</gadget>
<output>1/5 = around 0.2</output>

<result>1/5 = around 0.2</result>