The electricity consumption in the first half of the month is 50 degrees, and the second half of the month is 10% less than the first half. How much electricity is saved?
上半月用电50度，下半月比上半月节约10%，节约用电多少度？
<gadget id="calculator">10 / 100</gadget>
<output>1/10 = around 0.1</output>

<gadget id="calculator">50 * (1/10)</gadget>
<output>5</output>

<result>5</result>