A factory shipped a batch of coal and planned to burn 8 tons per day for 45 days. Actually save 10% of coal every day, so how many days can it be burned?
一个工厂运来一批煤，计划每天烧8吨，可以烧45天．实际每天节约煤10%，这样可以烧多少天？
<gadget id="calculator">8 * 45</gadget>
<output>360</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">8 * (9/10)</gadget>
<output>36/5 = around 7.2</output>

<gadget id="calculator">360 / (36/5)</gadget>
<output>50</output>

<result>50</result>