A cylindrical cup is filled with 6 liters of water, pour it into a conical cup with the same bottom and height, how many liters of water will remain after filling the conical cup.
一个圆柱体杯中盛满6升水，把它倒进一个与它等底等高的圆锥杯中，倒满圆锥杯后，还剩多少升水．
<gadget id="calculator">1 / 3</gadget>
<output>1/3 = around 0.333333</output>

<gadget id="calculator">1 - (1/3)</gadget>
<output>2/3 = around 0.666667</output>

<gadget id="calculator">6 * (2/3)</gadget>
<output>4</output>

<result>4</result>