There are 80 tons of cement in one batch, and (2/5) of the total tonnage is transported away for the first time, and (3/10) of the total tonnage is transported away for the second time, how many tons are transported in total in the two times.
一批水泥有80吨，第一次运走总吨数的(2/5)，第二次运走总吨数的(3/10)，两次一共运走多少吨．
<gadget id="calculator">2 / 5</gadget>
<output>2/5 = around 0.4</output>

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

<gadget id="calculator">(2/5) + (3/10)</gadget>
<output>7/10 = around 0.7</output>

<gadget id="calculator">80 * (7/10)</gadget>
<output>56</output>

<result>56</result>