1421 ÷ 9 = 157 R8
Let's divide 1421 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 (4) of the dividend behind the 1 and repeat the process: 14 / 9

Step 2:
9 goes into 14 1 times with a remainder of 5.
Write down 1 as next digit of of the result. 
Result so far: 1
Subtract 9 from 14 to get 5.
Bring next digit (2) of the dividend behind the 5 and repeat the process: 52 / 9

Step 3:
9 goes into 52 5 times with a remainder of 7.
Write down 5 as next digit of of the result. 
Result so far: 15
Subtract 45 from 52 to get 7.
Bring next digit (1) of the dividend behind the 7 and repeat the process: 71 / 9

Step 4:
9 goes into 71 7 times with a remainder of 8.
Write down 7 as next digit of of the result. 
Result so far: 157
Subtract 63 from 71 to get 8.

The final result is 157 with a remainder of 8.