A rope, first cut off its (2/5). Then cut off (3/5) meters, leaving 1.8 meters, how many meters is the original rope length?
一根绳子，先剪去它的(2/5)．再剪去(3/5)米，还剩下1.8米，原来绳长多少米？
<gadget id="calculator">3 / 5</gadget>
<output>3/5 = around 0.6</output>

<gadget id="calculator">(3/5) + 1.8</gadget>
<output>2.4</output>

<gadget id="calculator">2 / 5</gadget>
<output>2/5 = around 0.4</output>

<gadget id="calculator">1 - (2/5)</gadget>
<output>3/5 = around 0.6</output>

<gadget id="calculator">2.4 / (3/5)</gadget>
<output>4</output>

<result>4</result>