Xiaohong’s family plans to use 15 tons of water per month. Due to water conservation, only 12 tons were used in April. How much was the savings?
小红家计划每月用水15吨，由于节约用水，四月份只用了12吨，节约了百分之几？
<gadget id="calculator">15 - 12</gadget>
<output>3</output>

<gadget id="calculator">3 / 15</gadget>
<output>1/5 = around 0.2</output>

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