A company saved an average of 9 tons of water per day in the second quarter of last year. How many tons of water was saved in the second quarter?
某公司去年第二季度平均每天节约用水9吨，第二季度共节约用水多少吨？
<gadget id="calculator">30 + 31 + 30</gadget>
<output>91</output>

<gadget id="calculator">91 * 9</gadget>
<output>819</output>

<result>819</result>