Let's divide 25215215 by 390
We want to divide 25215215 by 390.

Let's proceed to step 1:
If we divide 2 by 390, we get 0 and a remainder of 2.
The number 0 becomes the next digit in our result. 
Result so far: 0.0
Subtracting 0 from 2 leaves us with 2.
Include the next digit (5) from the dividend after 2, then repeat: 25 / 390

Let's proceed to step 2:
25 divided by 390 is 0 with a remainder of 25.
The next digit of our result is 0. 
Result so far: 0.0
Deduct 0 from 25 and we're left with 25.
Append the next digit (2) from the dividend to 25 and continue with: 252 / 390

Step 3:
390 goes into 252 0 times with a remainder of 252.
The next digit of our result is 0. 
Result so far: 0.0
If we subtract 0 from 252, we get 252.
Bring next digit (1) of the dividend behind the 252 and repeat the process: 2521 / 390

On to step 4:
The number 390 fits into 2521 6 times, leaving a remainder of 181.
Put 6 as the next digit of the answer. 
Result so far: 6.0
Subtract 2340 from 2521 to get 181.
Take the next digit (5) from the dividend and append it to 181, then repeat: 1815 / 390

Moving on to step 5:
390 can be fit into 1815 4 times, resulting in a remainder of 255.
Record the quotient 4 as the next digit in the result. 
Result so far: 64.0
Subtract 1560 from 1815 to get 255.
Grab the next digit (2) from the dividend, add it to 255, then carry on: 2552 / 390

On to step 6:
2552 divided by 390 is 6 with a remainder of 212.
The number 6 becomes the next digit in our result. 
Result so far: 646.0
If we take 2340 away from 2552, we end up with 212.
Fetch the next digit (1) from the dividend, attach it to 212 and continue: 2121 / 390

Going ahead to step 7:
If we divide 2121 by 390, we get 5 and a remainder of 171.
Record the quotient 5 as the next digit in the result. 
Result so far: 6465.0
If we take 1950 away from 2121, we end up with 171.
Grab the next digit (5) from the dividend, add it to 171, then carry on: 1715 / 390

Step 8:
1715 divided by 390 is 4 with a remainder of 155.
Use 4 as the next digit of our solution. 
Result so far: 64654.0
The remainder is 155 after subtracting 1560 from 1715.
Since there are no more digits in the dividend, we add a zero to the remainder making it 1550, and continue the process.

Going ahead to step 9:
If we divide 1550 by 390, we get 3 and a remainder of 380.
Record the quotient 3 as the next digit in the result. 
Result so far: 64654.3
Deduct 1170 from 1550 and we're left with 380.
Since there are no more digits in the dividend, we add a zero to the remainder making it 3800, and continue the process.

On to step 10:
390 goes into 3800 9 times with a remainder of 290.
The next digit of our result is 9. 
Result so far: 64654.39
Subtract 3510 from 3800 to get 290.
Since there are no more digits in the dividend, we add a zero to the remainder making it 2900, and continue the process.

Let's proceed to step 11:
The number 390 fits into 2900 7 times, leaving a remainder of 170.
Write down 7 as next digit of the result. 
Result so far: 64654.397
If we take 2730 away from 2900, we end up with 170.
Since there are no more digits in the dividend, we add a zero to the remainder making it 1700, and continue the process.

Advancing to step 12:
390 can be fit into 1700 4 times, resulting in a remainder of 140.
Use 4 as the next digit of our solution. 
Result so far: 64654.3974
If we subtract 1560 from 1700, we get 140.
Since there are no more digits in the dividend, we add a zero to the remainder making it 1400, and continue the process.

Let's proceed to step 13:
390 goes into 1400 3 times with a remainder of 230.
The next digit of our result is 3. 
Result so far: 64654.39743
If we subtract 1170 from 1400, we get 230.
Since there are no more digits in the dividend, we add a zero to the remainder making it 2300, and continue the process.

Going ahead to step 14:
390 can be fit into 2300 5 times, resulting in a remainder of 350.
Write down 5 as next digit of the result. 
Result so far: 64654.397435
The remainder is 350 after subtracting 1950 from 2300.
Since there are no more digits in the dividend, we add a zero to the remainder making it 3500, and continue the process.

Going ahead to step 15:
390 can be fit into 3500 8 times, resulting in a remainder of 380.
The number 8 becomes the next digit in our result. 
Result so far: 64654.3974358
If we subtract 3120 from 3500, we get 380.
Since there are no more digits in the dividend, we add a zero to the remainder making it 3800, and continue the process.

Let's proceed to step 16:
If we divide 3800 by 390, we get 9 and a remainder of 290.
Write down 9 as next digit of the result. 
Result so far: 64654.39743589
The remainder is 290 after subtracting 3510 from 3800.
Since there are no more digits in the dividend, we add a zero to the remainder making it 2900, and continue the process.

The final outcome is 64654.39743589, with a leftover of 2.9e-07.