Melt and cast a cube square steel with two sides of 3 decimeters long into a rectangular parallelepiped steel with a cross-section length of 5 cm and a width of 4 cm. How many decimeters is the length of this steel?
把两个棱长都是3分米的正方体方钢熔铸成一根横截面长5厘米，宽4厘米的长方体钢材，这根钢材的长是多少分米？
<gadget id="calculator">5 / 10</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">4 / 10</gadget>
<output>2/5 = around 0.4</output>

<gadget id="calculator">(1/2) * (2/5)</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">2 / (1/5)</gadget>
<output>10</output>

<gadget id="calculator">3 * 3 * 3 * 10</gadget>
<output>270</output>

<result>270</result>