81521 ÷ 9 = 9057 R8
Alright, let's work through the division of 81521 by 9 step by step.

Step 1:
9 goes into 8 0 times with a remainder of 8.
Write down 0 as next digit of of the result. 
Result so far: 0
Subtract 0 from 8 to get 8.
Bring next digit (1) of the dividend behind the 8 and repeat the process: 81 / 9

Step 2:
9 goes into 81 9 times with a remainder of 0.
Write down 9 as next digit of of the result. 
Result so far: 9
Subtract 81 from 81 to get 0.
Bring next digit (5) of the dividend behind the 0 and repeat the process: 5 / 9

Step 3:
9 goes into 5 0 times with a remainder of 5.
Write down 0 as next digit of of the result. 
Result so far: 90
Subtract 0 from 5 to get 5.
Bring next digit (2) of the dividend behind the 5 and repeat the process: 52 / 9

Step 4:
9 goes into 52 5 times with a remainder of 7.
Write down 5 as next digit of of the result. 
Result so far: 905
Subtract 45 from 52 to get 7.
Bring next digit (1) of the dividend behind the 7 and repeat the process: 71 / 9

Step 5:
9 goes into 71 7 times with a remainder of 8.
Write down 7 as next digit of of the result. 
Result so far: 9057
Subtract 63 from 71 to get 8.

The final result is 9057 with a remainder of 8.