We're dividing 661399 by 25 
We want to divide 661399 by 25.

Step 1:
25 goes into 6 0 times with a remainder of 6.
Record the quotient 0 as the next digit in the result. 
Result so far: 0.0
Subtracting 0 from 6 leaves us with 6.
Take the next digit (6) from the dividend and append it to 6, then repeat: 66 / 25

Going ahead to step 2:
25 can be fit into 66 2 times, resulting in a remainder of 16.
Write down 2 as next digit of the result. 
Result so far: 2.0
Subtract 50 from 66 to get 16.
Include the next digit (1) from the dividend after 16, then repeat: 161 / 25

Moving on to step 3:
25 can be fit into 161 6 times, resulting in a remainder of 11.
Record the quotient 6 as the next digit in the result. 
Result so far: 26.0
Deduct 150 from 161 and we're left with 11.
Take the next digit (3) from the dividend and append it to 11, then repeat: 113 / 25

Let's proceed to step 4:
25 goes into 113 4 times with a remainder of 13.
Use 4 as the next digit of our solution. 
Result so far: 264.0
Deduct 100 from 113 and we're left with 13.
Take the next digit (9) from the dividend and append it to 13, then repeat: 139 / 25

Going ahead to step 5:
25 goes into 139 5 times with a remainder of 14.
Use 5 as the next digit of our solution. 
Result so far: 2645.0
If we take 125 away from 139, we end up with 14.
Take the next digit (9) from the dividend and append it to 14, then repeat: 149 / 25

Going ahead to step 6:
If we divide 149 by 25, we get 5 and a remainder of 24.
Put 5 as the next digit of the answer. 
Result so far: 26455.0
If we subtract 125 from 149, we get 24.
Since there are no more digits in the dividend, we add a zero to the remainder making it 240, and continue the process.

Going ahead to step 7:
240 divided by 25 is 9 with a remainder of 15.
Write down 9 as next digit of the result. 
Result so far: 26455.9
Deduct 225 from 240 and we're left with 15.
Since there are no more digits in the dividend, we add a zero to the remainder making it 150, and continue the process.

Advancing to step 8:
25 goes into 150 6 times with a remainder of 0.
Write down 6 as next digit of the result. 
Result so far: 26455.96
The remainder is 0 after subtracting 150 from 150.
Since there are no more digits in the dividend, we add a zero to the remainder making it 0, and continue the process.

Let's proceed to step 9:
25 can be fit into 0 0 times, resulting in a remainder of 0.
The next digit of our result is 0. 
Result so far: 26455.96
If we take 0 away from 0, we end up with 0.
Since there are no more digits in the dividend, we add a zero to the remainder making it 0, and continue the process.

Step 10:
0 divided by 25 is 0 with a remainder of 0.
Use 0 as the next digit of our solution. 
Result so far: 26455.96
Subtracting 0 from 0 leaves us with 0.
Since there are no more digits in the dividend, we add a zero to the remainder making it 0, and continue the process.

The quotient of the division is 26455.96, and the remainder is 0.0.