The original price of a bicycle is 800 yuan. What is the price of this bicycle after a 20% discount?
一辆自行车原价800元，这辆自行车打八折后的价钱是多少元．
<gadget id="calculator">80 / 100</gadget>
<output>4/5 = around 0.8</output>

<gadget id="calculator">800 * (4/5)</gadget>
<output>640</output>

<result>640</result>