A tailor uses a piece of cloth as an ornament, and uses up (2/5) for the first time, and (1/2) for the second time, what percentage of the cloth is left?
裁缝师傅用一块布做装饰品，第一次用去(2/5)，第二次用去(1/2)，这块布料还剩下几分之几？
<gadget id="calculator">2 / 5</gadget>
<output>2/5 = around 0.4</output>

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

<gadget id="calculator">1 - (2/5) - (1/2)</gadget>
<output>1/10 = around 0.1</output>

<result>1/10 = around 0.1</result>