Suguo Supermarket sold (2/5) tons of biscuits in August, and sold (1/10) less in September than in August. How many tons of biscuits were sold in September?
苏果超市八月份卖出饼干(2/5)吨，九月份比八月份少卖(1/10)，九月份卖出饼干多少吨？
<gadget id="calculator">2 / 5</gadget>
<output>2/5 = around 0.4</output>

<gadget id="calculator">1 / 10</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">(2/5) * (9/10)</gadget>
<output>9/25 = around 0.36</output>

<result>9/25 = around 0.36</result>