3661 ÷ 4 = 915 R1
We're going to perform division on 3661 with 4 as the divisor.

Step 1:
4 goes into 3 0 times with a remainder of 3.
Write down 0 as next digit of of the result. 
Result so far: 0
Subtract 0 from 3 to get 3.
Bring next digit (6) of the dividend behind the 3 and repeat the process: 36 / 4

Step 2:
4 goes into 36 9 times with a remainder of 0.
Write down 9 as next digit of of the result. 
Result so far: 9
Subtract 36 from 36 to get 0.
Bring next digit (6) of the dividend behind the 0 and repeat the process: 6 / 4

Step 3:
4 goes into 6 1 times with a remainder of 2.
Write down 1 as next digit of of the result. 
Result so far: 91
Subtract 4 from 6 to get 2.
Bring next digit (1) of the dividend behind the 2 and repeat the process: 21 / 4

Step 4:
4 goes into 21 5 times with a remainder of 1.
Write down 5 as next digit of of the result. 
Result so far: 915
Subtract 20 from 21 to get 1.

The final result is 915 with a remainder of 1.