84521 ÷ 5 = 16904 R1
We're going to perform division on 84521 with 5 as the divisor.

Step 1:
5 goes into 8 1 times with a remainder of 3.
Write down 1 as next digit of of the result. 
Result so far: 1
Subtract 5 from 8 to get 3.
Bring next digit (4) of the dividend behind the 3 and repeat the process: 34 / 5

Step 2:
5 goes into 34 6 times with a remainder of 4.
Write down 6 as next digit of of the result. 
Result so far: 16
Subtract 30 from 34 to get 4.
Bring next digit (5) of the dividend behind the 4 and repeat the process: 45 / 5

Step 3:
5 goes into 45 9 times with a remainder of 0.
Write down 9 as next digit of of the result. 
Result so far: 169
Subtract 45 from 45 to get 0.
Bring next digit (2) of the dividend behind the 0 and repeat the process: 2 / 5

Step 4:
5 goes into 2 0 times with a remainder of 2.
Write down 0 as next digit of of the result. 
Result so far: 1690
Subtract 0 from 2 to get 2.
Bring next digit (1) of the dividend behind the 2 and repeat the process: 21 / 5

Step 5:
5 goes into 21 4 times with a remainder of 1.
Write down 4 as next digit of of the result. 
Result so far: 16904
Subtract 20 from 21 to get 1.

The final result is 16904 with a remainder of 1.