After folding an 80 cm long string twice in half, use scissors to cut it at the midpoint, and take the longest and shortest lengths. What is the sum of the lengths of the two lengths in centimeters?
将一根长80厘米的细绳对折两次后，用剪刀在中点处剪开，取其中长度最长的与最短的各一段，这两段绳的绳长之和是多少厘米．
<gadget id="calculator">1 / 2</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">80 * (1/2) * (1/2)</gadget>
<output>20</output>

<gadget id="calculator">1 / 4</gadget>
<output>1/4 = around 0.25</output>

<gadget id="calculator">80 * (1/4) * (1/2)</gadget>
<output>10</output>

<gadget id="calculator">20 + 10</gadget>
<output>30</output>

<result>30</result>