One barrel of oil has used up (1/5) kilograms, and there is still (2/3), how many kilograms is this barrel of oil? What is the column
一桶油用去了(1/5)千克，还剩(2/3)，求这桶油有多少千克？列式为多少
<gadget id="calculator">1 / 5</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">2 / 3</gadget>
<output>2/3 = around 0.666667</output>

<gadget id="calculator">1 - (2/3)</gadget>
<output>1/3 = around 0.333333</output>

<gadget id="calculator">(1/5) / (1/3)</gadget>
<output>3/5 = around 0.6</output>

<result>3/5 = around 0.6</result>