Xiao Min’s family paid 30 yuan for electricity last month, and this month’s electricity bill is less than last month (1/4). How much more did her family pay for electricity last month than this month?
小敏家上月交电费30元，这个月电费比上个月少交了(1/4)，她家上个月比这个月多交电费多少元？
<gadget id="calculator">1 / 4</gadget>
<output>1/4 = around 0.25</output>

<gadget id="calculator">30 * (1/4)</gadget>
<output>15/2 = around 7.5</output>

<result>15/2 = around 7.5</result>