A piece of steel is 55 meters long, use up (1/5) of it, what is the remaining piece of steel
一段钢材长是55米，用去它的(1/5)，剩下这段钢材的多少
<gadget id="calculator">5 / 1</gadget>
<output>5</output>

<gadget id="calculator">4 / 5</gadget>
<output>4/5 = around 0.8</output>

<result>4/5 = around 0.8</result>