30857 ÷ 2 = 15428 R1
We're going to perform division on 30857 with 2 as the divisor.

Step 1:
2 goes into 3 1 times with a remainder of 1.
Write down 1 as next digit of of the result. 
Result so far: 1
Subtract 2 from 3 to get 1.
Bring next digit (0) of the dividend behind the 1 and repeat the process: 10 / 2

Step 2:
2 goes into 10 5 times with a remainder of 0.
Write down 5 as next digit of of the result. 
Result so far: 15
Subtract 10 from 10 to get 0.
Bring next digit (8) of the dividend behind the 0 and repeat the process: 8 / 2

Step 3:
2 goes into 8 4 times with a remainder of 0.
Write down 4 as next digit of of the result. 
Result so far: 154
Subtract 8 from 8 to get 0.
Bring next digit (5) of the dividend behind the 0 and repeat the process: 5 / 2

Step 4:
2 goes into 5 2 times with a remainder of 1.
Write down 2 as next digit of of the result. 
Result so far: 1542
Subtract 4 from 5 to get 1.
Bring next digit (7) of the dividend behind the 1 and repeat the process: 17 / 2

Step 5:
2 goes into 17 8 times with a remainder of 1.
Write down 8 as next digit of of the result. 
Result so far: 15428
Subtract 16 from 17 to get 1.

The final result is 15428 with a remainder of 1.