Master Zhang used a stainless steel pipe to make an anti-theft door. He cut off (3/5) for the first time, and cut off (1/5) meters for the second time. At this time, there are still (7/10) meters left. Then this How long is the steel pipe?
张师傅用一根不锈钢管制作防盗门，第一次截去(3/5)，第二次又截去(1/5)米，这时还剩下(7/10)米，那么这根钢管原来长多少米？
<gadget id="calculator">1 / 5</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">7 / 10</gadget>
<output>7/10 = around 0.7</output>

<gadget id="calculator">(1/5) + (7/10)</gadget>
<output>9/10 = around 0.9</output>

<gadget id="calculator">3 / 5</gadget>
<output>3/5 = around 0.6</output>

<gadget id="calculator">1 - (3/5)</gadget>
<output>2/5 = around 0.4</output>

<gadget id="calculator">(9/10) / (2/5)</gadget>
<output>9/4 = around 2.25</output>

<result>9/4 = around 2.25</result>