There are two iron wires, the first one is long (7/10) and the second one is shorter (3/10) meters, how long is the second iron wire?
有两根铁丝，第一根长(7/10)，比第二根短(3/10)米，第二根铁丝有多长？
<gadget id="calculator">7 / 10</gadget>
<output>7/10 = around 0.7</output>

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

<gadget id="calculator">(7/10) + (3/10)</gadget>
<output>1</output>

<result>1</result>