In the first half of the year (6 months), the two families of Xiaoming and Xiaojun shared 180 tons of water. How many tons of water does each household use per month on average?
小明小军两家上半年(6个月)一共用水180吨，平均每户每个月用水多少吨？
<gadget id="calculator">180 / 6 / 2</gadget>
<output>15</output>

<result>15</result>