A 10-meter-long steel is cut off (2/5) for the first time, and (1/2) is cut off for the second time, how many meters are left?
一根10米长的钢材第一次截下它的(2/5)，第二次截下它的(1/2)，还剩多少米．
<gadget id="calculator">2 / 5</gadget>
<output>2/5 = around 0.4</output>

<gadget id="calculator">10 * (2/5)</gadget>
<output>4</output>

<gadget id="calculator">1 / 2</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">10 * (1/2)</gadget>
<output>5</output>

<gadget id="calculator">10 - 4 - 5</gadget>
<output>1</output>

<result>1</result>