1 kg (4/5) is about the same size as 4 kg.
1千克的(4/5)和4千克的多少一样大．
<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>