A barrel of oil, 35 kg is used for the first time, (1/5) kg of the first time is used for the second time, leaving 12 kg. How many kilograms does this barrel of oil weigh?
一桶油，第一次用去35千克，第二次用去第一次的(1/5)千克，还剩12千克．这桶油原重多少千克？
<gadget id="calculator">1 / 5</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">35 * (1/5)</gadget>
<output>7</output>

<gadget id="calculator">35 + 7 + 12</gadget>
<output>54</output>

<result>54</result>