21608 ÷ 5 = 4321 R3
We're going to perform division on 21608 with 5 as the divisor.

Step 1:
5 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 / 5

Step 2:
5 goes into 21 4 times with a remainder of 1.
Write down 4 as next digit of of the result. 
Result so far: 4
Subtract 20 from 21 to get 1.
Bring next digit (6) of the dividend behind the 1 and repeat the process: 16 / 5

Step 3:
5 goes into 16 3 times with a remainder of 1.
Write down 3 as next digit of of the result. 
Result so far: 43
Subtract 15 from 16 to get 1.
Bring next digit (0) of the dividend behind the 1 and repeat the process: 10 / 5

Step 4:
5 goes into 10 2 times with a remainder of 0.
Write down 2 as next digit of of the result. 
Result so far: 432
Subtract 10 from 10 to get 0.
Bring next digit (8) of the dividend behind the 0 and repeat the process: 8 / 5

Step 5:
5 goes into 8 1 times with a remainder of 3.
Write down 1 as next digit of of the result. 
Result so far: 4321
Subtract 5 from 8 to get 3.

The final result is 4321 with a remainder of 3.