Xiaoming's house used to use an average of 150 kWh of electricity per month. After switching to energy-saving lamps, the monthly electricity consumption is 60 kWh less than before. What percentage is the current electricity consumption? According to this calculation, if 40,000 households in the county switch to energy-saving lamps, how many kilowatt-hours of electricity can be saved in a month?
小明家原来平均每月用电150千瓦时，改用节能灯以后，每月的用电量比原来节约60千瓦时，现在的用电量是原来的百分之几？照这样计算，如果全县4万户家庭都改用节能灯，一个月可节约用电多少千瓦时？
<gadget id="calculator">60 * 40_000</gadget>
<output>2_400_000</output>

<result>2_400_000</result>