A 6-meter-long iron wire, 2.6 meters are used up, how much more meters are left than used up?
一根长6米的铁丝，用去2.6米，剩下的比用去的多多少米？
<gadget id="calculator">6 - 2.6</gadget>
<output>3.4</output>

<gadget id="calculator">3.4 - 2.6</gadget>
<output>0.8</output>

<result>0.8</result>