A rope is divided into three sections. The first section is 3.8 meters long, the second section is 0.4 meters shorter than the first section, and the third section is 1.5 meters long. How long is the rope?
一根绳子分成三段，第一段长3.8米，第二段比第一段短0.4米，第三段长1.5米，这根绳子长多少米？
<gadget id="calculator">3.8 - 0.4</gadget>
<output>3.4</output>

<gadget id="calculator">3.8 + 3.4 + 1.5</gadget>
<output>8.7</output>

<result>8.7</result>