The fruit shop shipped a batch of fruit, sold (4/5) tons on the first day, sold (3/10) tons on the second day, and left (1/2) tons, and sold more than the rest How many tons?
水果店运来一批水果，第一天卖出(4/5)吨，第二天卖出(3/10)吨，还剩下(1/2)吨，卖出的比剩下的多多少吨？
<gadget id="calculator">4 / 5</gadget>
<output>4/5 = around 0.8</output>

<gadget id="calculator">3 / 10</gadget>
<output>3/10 = around 0.3</output>

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

<gadget id="calculator">(3/10) - (1/2)</gadget>
<output>-1/5 = around -0.2</output>

<gadget id="calculator">(4/5) + (-1/5)</gadget>
<output>3/5 = around 0.6</output>

<result>3/5 = around 0.6</result>