A stationery box is 36 yuan after a 20% price reduction. How much is the price of this stationery box reduced?
一种文具盒降价20%后是36元．这种文具盒价钱降低了多少元？
<gadget id="calculator">20 / 100</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">1 - (1/5)</gadget>
<output>4/5 = around 0.8</output>

<gadget id="calculator">36 / (4/5)</gadget>
<output>45</output>

<gadget id="calculator">45 - 36</gadget>
<output>9</output>

<result>9</result>