A piece of cloth is (8/5) m long, if (1/5) m is used up, how much m is left?
一块布长(8/5)m，用去(1/5)m，还剩多少m．
<gadget id="calculator">8 / 5</gadget>
<output>8/5 = around 1.6</output>

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

<gadget id="calculator">(8/5) - (1/5)</gadget>
<output>7/5 = around 1.4</output>

<result>7/5 = around 1.4</result>