Uncle Zhang received 2 tons of watermelons, sold (1/8) of the total on the first day, and sold (2/7) of the total on the second day, what fraction of the total is left?
张大伯收了2吨西瓜，第一天卖出总数的(1/8)，第二天卖出总数的(2/7)，还剩总数的几分之几？
<gadget id="calculator">1 / 8</gadget>
<output>1/8 = around 0.125</output>

<gadget id="calculator">2 / 7</gadget>
<output>2/7 = around 0.285714</output>

<gadget id="calculator">1 - (1/8) - (2/7)</gadget>
<output>33/56 = around 0.589286</output>

<result>33/56 = around 0.589286</result>