685 ÷ 4 = 171 R1
We're going to perform division on 685 with 4 as the divisor.

Step 1:
4 goes into 6 1 times with a remainder of 2.
Write down 1 as next digit of of the result. 
Result so far: 1
Subtract 4 from 6 to get 2.
Bring next digit (8) of the dividend behind the 2 and repeat the process: 28 / 4

Step 2:
4 goes into 28 7 times with a remainder of 0.
Write down 7 as next digit of of the result. 
Result so far: 17
Subtract 28 from 28 to get 0.
Bring next digit (5) of the dividend behind the 0 and repeat the process: 5 / 4

Step 3:
4 goes into 5 1 times with a remainder of 1.
Write down 1 as next digit of of the result. 
Result so far: 171
Subtract 4 from 5 to get 1.

The final result is 171 with a remainder of 1.