A rubber rope is 3.6 meters long, and it is 7.2 meters long after being pulled hard. How much longer is it than the original?
一根橡皮绳长3.6米，用力拉后长7.2米，比原来长了多少米？
<gadget id="calculator">7.2 - 3.6</gadget>
<output>3.6</output>

<result>3.6</result>