A steel pipe is 9 meters long, and 3.6 meters are used up. How much longer is the rest than the used one?
一根钢管长9米，用去了3.6米，剩下的比用去的长多少米？
<gadget id="calculator">9 - 3.6 - 3.6</gadget>
<output>1.8</output>

<result>1.8</result>