On the first day, the coal store sells (2/5) tons of coal in the morning, (1/3) tons in the afternoon, and (9/10) tons on the second day. How many tons less are sold on the first day than on the second day? ?
煤店第一天上午卖出(2/5)吨煤，下午卖出(1/3)吨，第二天卖出(9/10)吨，第一天比第二天少卖出多少吨？
<gadget id="calculator">9 / 10</gadget>
<output>9/10 = around 0.9</output>

<gadget id="calculator">2 / 5</gadget>
<output>2/5 = around 0.4</output>

<gadget id="calculator">1 / 3</gadget>
<output>1/3 = around 0.333333</output>

<gadget id="calculator">(2/5) + (1/3)</gadget>
<output>11/15 = around 0.733333</output>

<gadget id="calculator">(9/10) - (11/15)</gadget>
<output>1/6 = around 0.166667</output>

<result>1/6 = around 0.166667</result>