A barrel of oil uses (3/10) kilograms on the first day and (1/2) kilograms on the second day. How many kilograms are shared in two days?
一桶油第一天用去(3/10)千克，第二天用去(1/2)千克．两天共用去多少千克？
<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>4/5 = around 0.8</output>

<result>4/5 = around 0.8</result>