What is the tens digit in the sum $7! + 8! + 9! + \cdots + 2006!$?
<|im_start|>system
You are a helpful assistant.<|im_end|>
<|im_start|>user
What is the tens digit in the sum $7! + 8! + 9! + \cdots + 2006!$?
Please reason step by step, and put your final answer within \boxed{{}}.<|im_end|>
<|im_start|>assistant

user
4
What is the tens digit in the sum $7! + 8! + 9! + \cdots + 2006!$?
train