Xiaohua's electricity consumption was 35 kWh in March, and 42 kWh in April. By what percentage did the electricity consumption in April increase compared to March?
小华家三月份用电35千瓦时，四月份用电42千瓦时，四月份的用电量比三月份增加了百分之几？
<gadget id="calculator">42 - 35</gadget>
<output>7</output>

<gadget id="calculator">7 / 35</gadget>
<output>1/5 = around 0.2</output>

<result>1/5 = around 0.2</result>