High-efficiency energy-saving lamps have the characteristics of high brightness, no color difference, stable light effect, and energy saving and money saving. If a 40-watt ordinary incandescent lamp consumes 0.2 kilowatt-hours of electricity a day on average, how much kilowatt-hours of electricity will be consumed at most in a day after being replaced with high-efficiency energy-saving lamps?
高效节能灯具有高亮度、无色差、光效稳定、节电省钱的特点，它的耗电量是普通白炽灯平均一天耗电的(3/5)～(4/5)．如果一个40瓦的普通白炽灯平均一天耗电0.2千瓦时，那么，换上高效节能灯后，一天最多耗电多少千瓦时？
<gadget id="calculator">4 / 5</gadget>
<output>4/5 = around 0.8</output>

<gadget id="calculator">0.2 * (4/5)</gadget>
<output>0.16</output>

<result>0.16</result>