Survey the pattern and Formalize the following:
 
9 \(\times\) 9 \(=\) 81 
 
99 \(\times\) 99 \(=\) 9801
 
999 \(\times\) 999 \(=\) 998001
 
9999 \(\times\) 9999 \(=\)
 
99999 \(\times\) 99999 \(=\)