<|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
 Fill in the 3×3 square grid with the numbers 1, 2, 3,..., 9, such that the numbers increase from top to bottom in each column and from left to right in each row. If the number 4 is fixed in the center position, calculate the number of different ways to fill the grid. Express your answer as a numerical value. 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
12
Fill in the 3×3 square grid with the numbers 1, 2, 3,..., 9, such that the numbers increase from top to bottom in each column and from left to right in each row. If the number 4 is fixed in the center position, calculate the number of different ways to fill the grid. Express your answer as a numerical value.
test