Xiaohua's family used 150 tons of water last year, and 68.75 tons in the first half of the year. How many tons more water will be used in the second half of the year than in the first half?
小华家去年全年用水150吨，上半年用水68.75吨，下半年比上半年多用水多少吨？
<gadget id="calculator">150 - 68.75 - 68.75</gadget>
<output>12.5</output>

<result>12.5</result>