The cafeteria uses 10 tons of water in September and 8 tons of water in October. By what percentage is the water tonnage saved in October compared to September?
食堂九月份用水10吨，十月份用水8吨．十月份用水吨数比九月份节约百分之几？
<gadget id="calculator">10 - 8</gadget>
<output>2</output>

<gadget id="calculator">2 / 10</gadget>
<output>1/5 = around 0.2</output>

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