To build a road, the full length (1/10) was repaired on the first day, the full length (2/15) was repaired on the second day, and the full length (4/15) was repaired on the third day. How much?
修一条公路，第一天修了全长的(1/10)，第二修了全长的(2/15)，第三天修了全长的(4/15)，三天共修全长的几分之几？
<gadget id="calculator">1 / 10</gadget>
<output>1/10 = around 0.1</output>

<gadget id="calculator">2 / 15</gadget>
<output>2/15 = around 0.133333</output>

<gadget id="calculator">4 / 15</gadget>
<output>4/15 = around 0.266667</output>

<gadget id="calculator">(1/10) + (2/15) + (4/15)</gadget>
<output>1/2 = around 0.5</output>

<result>1/2 = around 0.5</result>