The cafeteria used 4.5 tons of coal in October, and it saved (1/10) in November compared with October. How many tons was saved in November compared with October?
食堂十月份用煤4.5吨，十一月份比十月份节约(1/10)，十一月份比十月份节约多少吨？
<gadget id="calculator">1 / 10</gadget>
<output>1/10 = around 0.1</output>

<gadget id="calculator">4.5 * (1/10)</gadget>
<output>0.45</output>

<result>0.45</result>