<|im_start|>system
You are a helpful assistant. You first think about the reasoning process in the mind and then provide the user with the answer. You should try to truely solve the question by yourself without cheating.  <|im_end|>
<|im_start|>user
 A telecommunications company launched a series of mobile phone card numbers. The first seven digits of the card number are fixed, and the last four digits range from "0000" to "9999", making a total of 10,000 numbers. The company stipulates that any card number whose last four digits contain the number "6" or "8" will be designated as a "Golden Rabbit Card". Calculate the number of "Golden Rabbit Cards" in this series. Express your answer as a whole number. Show your work in <think> </think> tags. And return the final answer in <answer> </answer> tags.<|im_end|>
<|im_start|>assistant
Let me solve this step by step.
<think>
user
5904
A telecommunications company launched a series of mobile phone card numbers. The first seven digits of the card number are fixed, and the last four digits range from "0000" to "9999", making a total of 10,000 numbers. The company stipulates that any card number whose last four digits contain the number "6" or "8" will be designated as a "Golden Rabbit Card". Calculate the number of "Golden Rabbit Cards" in this series. Express your answer as a whole number.
test