21154 ÷ 6 = 3525 R4
Let's divide 21154 by 6.

Step 1:
6 goes into 2 0 times with a remainder of 2.
Write down 0 as next digit of of the result. 
Result so far: 0
Subtract 0 from 2 to get 2.
Bring next digit (1) of the dividend behind the 2 and repeat the process: 21 / 6

Step 2:
6 goes into 21 3 times with a remainder of 3.
Write down 3 as next digit of of the result. 
Result so far: 3
Subtract 18 from 21 to get 3.
Bring next digit (1) of the dividend behind the 3 and repeat the process: 31 / 6

Step 3:
6 goes into 31 5 times with a remainder of 1.
Write down 5 as next digit of of the result. 
Result so far: 35
Subtract 30 from 31 to get 1.
Bring next digit (5) of the dividend behind the 1 and repeat the process: 15 / 6

Step 4:
6 goes into 15 2 times with a remainder of 3.
Write down 2 as next digit of of the result. 
Result so far: 352
Subtract 12 from 15 to get 3.
Bring next digit (4) of the dividend behind the 3 and repeat the process: 34 / 6

Step 5:
6 goes into 34 5 times with a remainder of 4.
Write down 5 as next digit of of the result. 
Result so far: 3525
Subtract 30 from 34 to get 4.

The final result is 3525 with a remainder of 4.