20100 ÷ 5 = 4020 R0
Alright, let's work through the division of 20100 by 5 step by step.

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 (0) of the dividend behind the 2 and repeat the process: 20 / 5

Step 2:
5 goes into 20 4 times with a remainder of 0.
Write down 4 as next digit of of the result. 
Result so far: 4
Subtract 20 from 20 to get 0.
Bring next digit (1) of the dividend behind the 0 and repeat the process: 1 / 5

Step 3:
5 goes into 1 0 times with a remainder of 1.
Write down 0 as next digit of of the result. 
Result so far: 40
Subtract 0 from 1 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: 402
Subtract 10 from 10 to get 0.
Bring next digit (0) of the dividend behind the 0 and repeat the process: 0 / 5

Step 5:
5 goes into 0 0 times with a remainder of 0.
Write down 0 as next digit of of the result. 
Result so far: 4020
Subtract 0 from 0 to get 0.

The final result is 4020 with a remainder of 0.