The 1-ton (4/5) weighs the same as the 4-ton ((())/(())).
1吨的(4/5)和4吨的((())/(()))一样重．
<gadget id="calculator">4 / 5</gadget>
<output>4/5 = around 0.8</output>

<gadget id="calculator">(4/5) / 4</gadget>
<output>1/5 = around 0.2</output>

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

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