barrel of oil weighs 45 kilograms, and (2/9) is used for the first time, and (1/5) is used for the second time, how many kilograms are used for the two times?
一桶油重45千克，第一次用去它的(2/9)，第二次用去它的(1/5)，两次共用去多少千克？
<gadget id="calculator">2 / 9</gadget>
<output>2/9 = around 0.222222</output>

<gadget id="calculator">1 / 5</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">(2/9) + (1/5)</gadget>
<output>19/45 = around 0.422222</output>

<gadget id="calculator">45 * (19/45)</gadget>
<output>19</output>

<result>19</result>