Zhang Hong went to a boutique to buy some Christmas cards. Since the price of Christmas cards was reduced by 20%, she bought 6 more cards than originally planned. How many Christmas cards did Zhang Hong originally plan to buy?
张红到精品店购买一些圣诞卡，由于圣诞卡减价20%促销，因而她带的钱可比原计划多买6张，张红原计划要买多少张圣诞卡．
<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">(4/5) / (1/5)</gadget>
<output>4</output>

<gadget id="calculator">6 * 4</gadget>
<output>24</output>

<result>24</result>