Xiaodong’s electricity consumption was 120 kWh in October last year, 128 kWh in November, and 142 kWh in December. How much electricity has Xiaodong’s average monthly electricity consumption in the past few months?
小东家去年10月份用电120度，11月份用电128度，12月份用电142度．小东家这几个月平均每月用电多少度？
<gadget id="calculator">120 + 128 + 142</gadget>
<output>390</output>

<gadget id="calculator">390 / 3</gadget>
<output>130</output>

<result>130</result>