There is an oil drum with a capacity of 80 liters, half a barrel of oil is filled, after pouring out the oil (2/5), the remaining oil is poured into a small cylindrical barrel with a bottom area of 6 square decimeters. How many decimeters is the height of the small oil drum when it is full?
有一个可容80升的油桶，装了半桶油，倒出油的(2/5)后，把剩下的油再倒入底面积是6平方分米的圆柱形小桶中，正好装满，小油桶的高是多少分米？
<gadget id="calculator">1 / 2</gadget>
<output>1/2 = around 0.5</output>

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

<gadget id="calculator">1 - (2/5)</gadget>
<output>3/5 = around 0.6</output>

<gadget id="calculator">80 * (1/2) * (3/5)</gadget>
<output>24</output>

<gadget id="calculator">24 / 6</gadget>
<output>4</output>

<result>4</result>