390979 divided by 25 
Let's see how many times 25 fits into 390979.

Step 1:
25 goes into 3 0 times with a remainder of 3.
Put 0 as the next digit of the answer. 
Result so far: 0.0
Deduct 0 from 3 and we're left with 3.
Include the next digit (9) from the dividend after 3, then repeat: 39 / 25

On to step 2:
When dividing 39 by 25, we get 1 with a remainder of 14.
Use 1 as the next digit of our solution. 
Result so far: 1.0
If we subtract 25 from 39, we get 14.
Fetch the next digit (0) from the dividend, attach it to 14 and continue: 140 / 25

Step 3:
If we divide 140 by 25, we get 5 and a remainder of 15.
The number 5 becomes the next digit in our result. 
Result so far: 15.0
Subtracting 125 from 140 leaves us with 15.
Grab the next digit (9) from the dividend, add it to 15, then carry on: 159 / 25

Moving on to step 4:
The number 25 fits into 159 6 times, leaving a remainder of 9.
The number 6 becomes the next digit in our result. 
Result so far: 156.0
Deduct 150 from 159 and we're left with 9.
Fetch the next digit (7) from the dividend, attach it to 9 and continue: 97 / 25

On to step 5:
25 can be fit into 97 3 times, resulting in a remainder of 22.
Write down 3 as next digit of the result. 
Result so far: 1563.0
Subtracting 75 from 97 leaves us with 22.
Take the next digit (9) from the dividend and append it to 22, then repeat: 229 / 25

Let's proceed to step 6:
25 goes into 229 9 times with a remainder of 4.
The next digit of our result is 9. 
Result so far: 15639.0
If we subtract 225 from 229, we get 4.
Since there are no more digits in the dividend, we add a zero to the remainder making it 40, and continue the process.

Advancing to step 7:
If we divide 40 by 25, we get 1 and a remainder of 15.
The next digit of our result is 1. 
Result so far: 15639.1
Deduct 25 from 40 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.

Moving on to step 8:
150 divided by 25 is 6 with a remainder of 0.
The number 6 becomes the next digit in our result. 
Result so far: 15639.16
Subtracting 150 from 150 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.

Advancing to step 9:
The number 25 fits into 0 0 times, leaving a remainder of 0.
The number 0 becomes the next digit in our result. 
Result so far: 15639.16
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.

Advancing to step 10:
The number 25 fits into 0 0 times, leaving a remainder of 0.
Write down 0 as next digit of the result. 
Result so far: 15639.16
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 final outcome is 15639.16, with a leftover of 0.0.