25870410 divided by 639 
Let's see how many times 639 fits into 25870410.

Going ahead to step 1:
When dividing 2 by 639, we get 0 with a remainder of 2.
Write down 0 as next digit of the result. 
Result so far: 0.0
Deduct 0 from 2 and we're left with 2.
Append the next digit (5) from the dividend to 2 and continue with: 25 / 639

Advancing to step 2:
When dividing 25 by 639, we get 0 with a remainder of 25.
Put 0 as the next digit of the answer. 
Result so far: 0.0
Subtracting 0 from 25 leaves us with 25.
Grab the next digit (8) from the dividend, add it to 25, then carry on: 258 / 639

Going ahead to step 3:
639 goes into 258 0 times with a remainder of 258.
Use 0 as the next digit of our solution. 
Result so far: 0.0
If we subtract 0 from 258, we get 258.
Take the next digit (7) from the dividend and append it to 258, then repeat: 2587 / 639

Step 4:
When dividing 2587 by 639, we get 4 with a remainder of 31.
Write down 4 as next digit of the result. 
Result so far: 4.0
The remainder is 31 after subtracting 2556 from 2587.
Include the next digit (0) from the dividend after 31, then repeat: 310 / 639

Step 5:
639 can be fit into 310 0 times, resulting in a remainder of 310.
Write down 0 as next digit of the result. 
Result so far: 40.0
Deduct 0 from 310 and we're left with 310.
Include the next digit (4) from the dividend after 310, then repeat: 3104 / 639

Advancing to step 6:
639 can be fit into 3104 4 times, resulting in a remainder of 548.
Write down 4 as next digit of the result. 
Result so far: 404.0
If we subtract 2556 from 3104, we get 548.
Append the next digit (1) from the dividend to 548 and continue with: 5481 / 639

On to step 7:
The number 639 fits into 5481 8 times, leaving a remainder of 369.
Write down 8 as next digit of the result. 
Result so far: 4048.0
If we take 5112 away from 5481, we end up with 369.
Append the next digit (0) from the dividend to 369 and continue with: 3690 / 639

Going ahead to step 8:
When dividing 3690 by 639, we get 5 with a remainder of 495.
Put 5 as the next digit of the answer. 
Result so far: 40485.0
Subtracting 3195 from 3690 leaves us with 495.
Since there are no more digits in the dividend, we add a zero to the remainder making it 4950, and continue the process.

Going ahead to step 9:
639 goes into 4950 7 times with a remainder of 477.
The next digit of our result is 7. 
Result so far: 40485.7
The remainder is 477 after subtracting 4473 from 4950.
Since there are no more digits in the dividend, we add a zero to the remainder making it 4770, and continue the process.

Advancing to step 10:
When dividing 4770 by 639, we get 7 with a remainder of 297.
Use 7 as the next digit of our solution. 
Result so far: 40485.77
Deduct 4473 from 4770 and we're left with 297.
Since there are no more digits in the dividend, we add a zero to the remainder making it 2970, and continue the process.

In conclusion, the division gives 40485.77 with a balance of 0.297.