canteen burned 9 tons of coal in September, saving 25% compared to August. How many tons of coal was burned in August?
某食堂九月份烧煤9吨，比八月份节约25%，八月份烧煤多少吨？
<gadget id="calculator">25 / 100</gadget>
<output>1/4 = around 0.25</output>

<gadget id="calculator">1 - (1/4)</gadget>
<output>3/4 = around 0.75</output>

<gadget id="calculator">9 / (3/4)</gadget>
<output>12</output>

<result>12</result>