A 3-meter-long iron wire, cut off (2/5) meters for the first time, and cut off (3/10) meters for the second time, how many meters are left?
一根3米长的铁丝，第一次截去(2/5)米，第二次截去(3/10)米，还剩下多少米？
<gadget id="calculator">2 / 5</gadget>
<output>2/5 = around 0.4</output>

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

<gadget id="calculator">(2/5) + (3/10)</gadget>
<output>7/10 = around 0.7</output>

<gadget id="calculator">3 - (7/10)</gadget>
<output>23/10 = around 2.3</output>

<result>23/10 = around 2.3</result>