Coal consumption in September (9/10) tons is 10% less than that in August. How many tons of coal are used in August?
九月份用煤(9/10)吨，比八月份节约10%，八月份用煤多少吨．
<gadget id="calculator">9 / 10</gadget>
<output>9/10 = around 0.9</output>

<gadget id="calculator">10 / 100</gadget>
<output>1/10 = around 0.1</output>

<gadget id="calculator">1 - (1/10)</gadget>
<output>9/10 = around 0.9</output>

<gadget id="calculator">(9/10) / (9/10)</gadget>
<output>1</output>

<result>1</result>