Lili's house uses 200 degrees of electricity this month, which is 50 degrees less than last month. How much is the saving compared with last month?
丽丽家这个月用电200度，比上月节约了50度，比上月节约多少
<gadget id="calculator">200 + 50</gadget>
<output>250</output>

<gadget id="calculator">50 / 250</gadget>
<output>1/5 = around 0.2</output>

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