A rectangular steel plate is 2.4 meters long, 1 meter wide and weighs 6 kg. Cut out a disc with a diameter of 80 cm from above, what is the mass of this disc in kilograms?
一块长方形钢板长2.4米，宽1米，重6千克．从上面剪下一块直径是80厘米的圆片，这块圆片的质量是多少千克？
<gadget id="calculator">0.8 / 2</gadget>
<output>0.4</output>

<gadget id="calculator">0.4 ** 2</gadget>
<output>0.16</output>

<gadget id="calculator">2.4 * 1</gadget>
<output>2.4</output>

<gadget id="calculator">6 / 2.4</gadget>
<output>2.5</output>

<gadget id="calculator">3.14 * 0.16 * 2.5</gadget>
<output>1.256</output>

<result>1.256</result>