A barrel of oil weighs 40 kilograms, pour out (3/8), how many kilograms are left?
一桶油重40千克，倒出(3/8)，还剩多少千克？
<gadget id="calculator">3 / 8</gadget>
<output>3/8 = around 0.375</output>

<gadget id="calculator">40 * (3/8)</gadget>
<output>15</output>

<gadget id="calculator">40 - 15</gadget>
<output>25</output>

<result>25</result>