Xiaowen's family uses 6 tons of water per month, which is 9 tons less than before. How much is the savings?
小文家每月用水6吨，比原来每月节约用水9吨，节约了百分之几？
<gadget id="calculator">6 + 9</gadget>
<output>15</output>

<gadget id="calculator">9 / 15</gadget>
<output>3/5 = around 0.6</output>

<result>3/5 = around 0.6</result>