5100 ÷ 2 = 2550 R0
We're going to perform division on 5100 with 2 as the divisor.

Step 1:
2 goes into 5 2 times with a remainder of 1.
Write down 2 as next digit of of the result. 
Result so far: 2
Subtract 4 from 5 to get 1.
Bring next digit (1) of the dividend behind the 1 and repeat the process: 11 / 2

Step 2:
2 goes into 11 5 times with a remainder of 1.
Write down 5 as next digit of of the result. 
Result so far: 25
Subtract 10 from 11 to get 1.
Bring next digit (0) of the dividend behind the 1 and repeat the process: 10 / 2

Step 3:
2 goes into 10 5 times with a remainder of 0.
Write down 5 as next digit of of the result. 
Result so far: 255
Subtract 10 from 10 to get 0.
Bring next digit (0) of the dividend behind the 0 and repeat the process: 0 / 2

Step 4:
2 goes into 0 0 times with a remainder of 0.
Write down 0 as next digit of of the result. 
Result so far: 2550
Subtract 0 from 0 to get 0.

The final result is 2550 with a remainder of 0.