A steel pipe, its (5/10) is used for the first time, and its (3/10) is used for the second time. What fraction of this steel pipe is used less for the second time than for the first time?
一根钢管，第一次用去它的(5/10)，第二次用去它的(3/10)．第二次比第一次少用这根钢管的几分之几？
<gadget id="calculator">5 / 10</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">3 / 10</gadget>
<output>3/10 = around 0.3</output>

<gadget id="calculator">(1/2) - (3/10)</gadget>
<output>1/5 = around 0.2</output>

<result>1/5 = around 0.2</result>