Xiaoqiang’s family used 70 kwh of electricity in May, which is 30 kwh less than last month. How much is the savings compared to last month?
小强家五月份用电70度，比上个月节约了30度，比上个月节约了百分之几？
<gadget id="calculator">70 + 30</gadget>
<output>100</output>

<gadget id="calculator">30 / 100</gadget>
<output>3/10 = around 0.3</output>

<result>3/10 = around 0.3</result>