A rectangular parallelepiped copper bar with a length of 1.8 meters and a cross section of a side length of 5 cm is square. If the copper bar weighs 8.9 kg per cubic decimeter, how many kilograms does the copper bar weigh in total?
一根长1.8米，横截面是边长5厘米的正方形的长方体铜条，铜条如果每立方分米重8.9千克，这根铜条共重多少千克？
<gadget id="calculator">1.8 * 10</gadget>
<output>18</output>

<gadget id="calculator">5 / 10</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">18 * (1/2) * (1/2) * 8.9</gadget>
<output>40.05</output>

<result>40.05</result>