19851 ÷ 9 = 2205 R6
Let's divide 19851 by 9.

Step 1:
9 goes into 1 0 times with a remainder of 1.
Write down 0 as next digit of of the result. 
Result so far: 0
Subtract 0 from 1 to get 1.
Bring next digit (9) of the dividend behind the 1 and repeat the process: 19 / 9

Step 2:
9 goes into 19 2 times with a remainder of 1.
Write down 2 as next digit of of the result. 
Result so far: 2
Subtract 18 from 19 to get 1.
Bring next digit (8) of the dividend behind the 1 and repeat the process: 18 / 9

Step 3:
9 goes into 18 2 times with a remainder of 0.
Write down 2 as next digit of of the result. 
Result so far: 22
Subtract 18 from 18 to get 0.
Bring next digit (5) of the dividend behind the 0 and repeat the process: 5 / 9

Step 4:
9 goes into 5 0 times with a remainder of 5.
Write down 0 as next digit of of the result. 
Result so far: 220
Subtract 0 from 5 to get 5.
Bring next digit (1) of the dividend behind the 5 and repeat the process: 51 / 9

Step 5:
9 goes into 51 5 times with a remainder of 6.
Write down 5 as next digit of of the result. 
Result so far: 2205
Subtract 45 from 51 to get 6.

The final result is 2205 with a remainder of 6.