Barrel A contains 18 kg of oil, which is 2 kg less than barrel B, and how much less than barrel B.
甲桶有油18千克，比乙桶少2千克，比乙桶少多少．
<gadget id="calculator">18 + 2</gadget>
<output>20</output>

<gadget id="calculator">2 / 20</gadget>
<output>1/10 = around 0.1</output>

<gadget id="calculator">100 / 100</gadget>
<output>1</output>

<gadget id="calculator">(1/10) * 1</gadget>
<output>1/10 = around 0.1</output>

<result>1/10 = around 0.1</result>