Xiaohong’s house used 12.5 tons of water last month, and this month it used 0.8 tons less water than last month. How many tons of water are shared in two months?
小红家上个月用水12.5吨，本月比上个月少用水0.8吨，两个月一共用水多少吨？
<gadget id="calculator">12.5 - 0.8</gadget>
<output>11.7</output>

<gadget id="calculator">11.7 + 12.5</gadget>
<output>24.2</output>

<result>24.2</result>