For a rope, use up the full length (3/10) for the first time, and use up 16 meters for the second time, leaving half of the full length. How long is this rope?
一根绳子，第一次用去全长的(3/10)，第二次，用去16米，还剩下全长的一半．这根绳子有多长？
<gadget id="calculator">3 / 10</gadget>
<output>3/10 = around 0.3</output>

<gadget id="calculator">1 / 2</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">1 - (3/10) - (1/2)</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">16 / (1/5)</gadget>
<output>80</output>

<result>80</result>