If each person saves 0.2 tons of water per month, how many tons of water can the students in your class save in a year?
如果每人每月节约0.2吨水，你们班学生一年能节约多少吨水．
<gadget id="calculator">50 * 0.2 * 12</gadget>
<output>120</output>

<result>120</result>