A notebook computer is now selling for 3600 yuan each, which is 10% cheaper than before. How much does each computer cost?
一种笔记本电脑，现在每台卖3600元，比原来每台优惠10%．原来每台这种电脑多少元？
<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">3_600 / (9/10)</gadget>
<output>4_000</output>

<result>4_000</result>