The store shipped 2 tons of watermelons, sold (1/5) of the total on the first day, and (1/10) of the total on the second day, what fraction of the total is left?
商店运来2吨西瓜，第一天卖出总数的(1/5)，第二天卖出总数的(1/10)，还剩总数的几分之几？
<gadget id="calculator">1 / 5</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">1 / 10</gadget>
<output>1/10 = around 0.1</output>

<gadget id="calculator">1 - (1/5) - (1/10)</gadget>
<output>7/10 = around 0.7</output>

<result>7/10 = around 0.7</result>