There is a cylindrical oil tank in Dongfeng Chemical Plant. The radius of the bottom surface measured from the inside is 4 meters, and the height is 20 meters. The oil tank has been injected with 1/4 of the oil volume. If a cubic decimeter of oil weighs 700 kilograms, how many kilograms does the oil weigh? (π takes 3)
东风化工厂有一个圆柱形油罐，从里面量的底面半径是4米，高是20米．油罐内已注入占容积(1/4)的石油．如果每立方分米石油重700千克，这些石油重多少千克？(π取3)
<gadget id="calculator">4 ** 2</gadget>
<output>16</output>

<gadget id="calculator">1 / 4</gadget>
<output>1/4 = around 0.25</output>

<gadget id="calculator">3 * 16 * 20 * (1/4)</gadget>
<output>240</output>

<gadget id="calculator">240 * 700</gadget>
<output>168_000</output>

<result>168_000</result>