To paint a rectangular billboard with a length of 2.4 meters and a width of 0.8 meters, 0.9kg of paint should be used per square meter. How many kilograms of paint is needed in total?
给一个长2.4米，宽0.8米的长方形宣传栏刷油漆，每平方米要用0.9kg油漆．一共需要多少千克油漆？
<gadget id="calculator">2.4 * 0.8 * 0.9</gadget>
<output>1.728</output>

<result>1.728</result>