Li Hong’s family used 45 kWh of electricity last month, but this month they saved 20%. How many kWh did they use this month?
李红家上月用电45千瓦时，这个月节约了20%，这个月用电多少千瓦时？
<gadget id="calculator">20 / 100</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">1 - (1/5)</gadget>
<output>4/5 = around 0.8</output>

<gadget id="calculator">45 * (4/5)</gadget>
<output>36</output>

<result>36</result>