25155912 ÷ 870 
Our goal is to divide 25155912 by 870.

Advancing to step 1:
2 divided by 870 is 0 with a remainder of 2.
The next digit of our result is 0. 
Result so far: 0.0
The remainder is 2 after subtracting 0 from 2.
Include the next digit (5) from the dividend after 2, then repeat: 25 / 870

Step 2:
870 can be fit into 25 0 times, resulting in a remainder of 25.
Record the quotient 0 as the next digit in the result. 
Result so far: 0.0
Deduct 0 from 25 and we're left with 25.
Take the next digit (1) from the dividend and append it to 25, then repeat: 251 / 870

Going ahead to step 3:
870 goes into 251 0 times with a remainder of 251.
Record the quotient 0 as the next digit in the result. 
Result so far: 0.0
The remainder is 251 after subtracting 0 from 251.
Bring next digit (5) of the dividend behind the 251 and repeat the process: 2515 / 870

Moving on to step 4:
If we divide 2515 by 870, we get 2 and a remainder of 775.
Record the quotient 2 as the next digit in the result. 
Result so far: 2.0
If we subtract 1740 from 2515, we get 775.
Append the next digit (5) from the dividend to 775 and continue with: 7755 / 870

Step 5:
870 can be fit into 7755 8 times, resulting in a remainder of 795.
Write down 8 as next digit of the result. 
Result so far: 28.0
Subtract 6960 from 7755 to get 795.
Include the next digit (9) from the dividend after 795, then repeat: 7959 / 870

On to step 6:
870 goes into 7959 9 times with a remainder of 129.
The next digit of our result is 9. 
Result so far: 289.0
If we take 7830 away from 7959, we end up with 129.
Append the next digit (1) from the dividend to 129 and continue with: 1291 / 870

Moving on to step 7:
When dividing 1291 by 870, we get 1 with a remainder of 421.
Use 1 as the next digit of our solution. 
Result so far: 2891.0
The remainder is 421 after subtracting 870 from 1291.
Append the next digit (2) from the dividend to 421 and continue with: 4212 / 870

Moving on to step 8:
4212 divided by 870 is 4 with a remainder of 732.
Use 4 as the next digit of our solution. 
Result so far: 28914.0
Subtracting 3480 from 4212 leaves us with 732.
Since there are no more digits in the dividend, we add a zero to the remainder making it 7320, and continue the process.

Let's proceed to step 9:
If we divide 7320 by 870, we get 8 and a remainder of 360.
Put 8 as the next digit of the answer. 
Result so far: 28914.8
If we subtract 6960 from 7320, we get 360.
Since there are no more digits in the dividend, we add a zero to the remainder making it 3600, and continue the process.

On to step 10:
870 can be fit into 3600 4 times, resulting in a remainder of 120.
The number 4 becomes the next digit in our result. 
Result so far: 28914.84
Subtracting 3480 from 3600 leaves us with 120.
Since there are no more digits in the dividend, we add a zero to the remainder making it 1200, and continue the process.

Moving on to step 11:
870 goes into 1200 1 times with a remainder of 330.
Write down 1 as next digit of the result. 
Result so far: 28914.841
If we take 870 away from 1200, we end up with 330.
Since there are no more digits in the dividend, we add a zero to the remainder making it 3300, and continue the process.

Advancing to step 12:
3300 divided by 870 is 3 with a remainder of 690.
Write down 3 as next digit of the result. 
Result so far: 28914.8413
Subtracting 2610 from 3300 leaves us with 690.
Since there are no more digits in the dividend, we add a zero to the remainder making it 6900, and continue the process.

Moving on to step 13:
870 can be fit into 6900 7 times, resulting in a remainder of 810.
Write down 7 as next digit of the result. 
Result so far: 28914.84137
The remainder is 810 after subtracting 6090 from 6900.
Since there are no more digits in the dividend, we add a zero to the remainder making it 8100, and continue the process.

On to step 14:
If we divide 8100 by 870, we get 9 and a remainder of 270.
Use 9 as the next digit of our solution. 
Result so far: 28914.841379
If we take 7830 away from 8100, we end up with 270.
Since there are no more digits in the dividend, we add a zero to the remainder making it 2700, and continue the process.

Let's proceed to step 15:
If we divide 2700 by 870, we get 3 and a remainder of 90.
The next digit of our result is 3. 
Result so far: 28914.8413793
Subtracting 2610 from 2700 leaves us with 90.
Since there are no more digits in the dividend, we add a zero to the remainder making it 900, and continue the process.

On to step 16:
900 divided by 870 is 1 with a remainder of 30.
Use 1 as the next digit of our solution. 
Result so far: 28914.84137931
If we take 870 away from 900, we end up with 30.
Since there are no more digits in the dividend, we add a zero to the remainder making it 300, and continue the process.

The final outcome is 28914.84137931, with a leftover of 3e-08.