Dad used two ropes with a length of 1.38 meters to tie up the newspapers. The interface shares a 0.3-meter rope. How long is the rope after it is connected?
爸爸用两条长度都是1.38米的绳子接起来捆扎报纸．接口处共用去绳子0.3米，接好后的绳子有多长？
<gadget id="calculator">1.38 - 0.3</gadget>
<output>1.08</output>

<gadget id="calculator">1.38 + 1.08</gadget>
<output>2.46</output>

<result>2.46</result>