There is a trapezoidal billboard at the entrance of a supermarket that needs to be painted. The average length of its upper and lower bottoms is 8 meters, and its height is 5 meters. If 2 kilograms of paint are used per square meter, how many kilograms of paint should be used to paint this billboard?
一个超市门口有一块梯形广告牌需要油漆，它的上下底的平均长度是8米，高是5米．如果每平方米用油漆2千克，油漆这块广告牌，至少要用油漆多少千克？
<gadget id="calculator">8 * 2</gadget>
<output>16</output>

<gadget id="calculator">5 / 2</gadget>
<output>5/2 = around 2.5</output>

<gadget id="calculator">16 * (5/2)</gadget>
<output>40</output>

<gadget id="calculator">40 * 2</gadget>
<output>80</output>

<result>80</result>