We're dividing 12879315 by 390 
Our goal is to divide 12879315 by 390.

Going ahead to step 1:
When dividing 1 by 390, we get 0 with a remainder of 1.
Record the quotient 0 as the next digit in the result. 
Result so far: 0.0
Deduct 0 from 1 and we're left with 1.
Append the next digit (2) from the dividend to 1 and continue with: 12 / 390

Going ahead to step 2:
When dividing 12 by 390, we get 0 with a remainder of 12.
The number 0 becomes the next digit in our result. 
Result so far: 0.0
Deduct 0 from 12 and we're left with 12.
Grab the next digit (8) from the dividend, add it to 12, then carry on: 128 / 390

Going ahead to step 3:
390 goes into 128 0 times with a remainder of 128.
Record the quotient 0 as the next digit in the result. 
Result so far: 0.0
If we subtract 0 from 128, we get 128.
Take the next digit (7) from the dividend and append it to 128, then repeat: 1287 / 390

Moving on to step 4:
If we divide 1287 by 390, we get 3 and a remainder of 117.
Put 3 as the next digit of the answer. 
Result so far: 3.0
Subtracting 1170 from 1287 leaves us with 117.
Append the next digit (9) from the dividend to 117 and continue with: 1179 / 390

Let's proceed to step 5:
390 goes into 1179 3 times with a remainder of 9.
Write down 3 as next digit of the result. 
Result so far: 33.0
Subtracting 1170 from 1179 leaves us with 9.
Take the next digit (3) from the dividend and append it to 9, then repeat: 93 / 390

Let's proceed to step 6:
The number 390 fits into 93 0 times, leaving a remainder of 93.
The number 0 becomes the next digit in our result. 
Result so far: 330.0
The remainder is 93 after subtracting 0 from 93.
Take the next digit (1) from the dividend and append it to 93, then repeat: 931 / 390

Going ahead to step 7:
390 goes into 931 2 times with a remainder of 151.
The number 2 becomes the next digit in our result. 
Result so far: 3302.0
Subtracting 780 from 931 leaves us with 151.
Fetch the next digit (5) from the dividend, attach it to 151 and continue: 1515 / 390

Going ahead to step 8:
When dividing 1515 by 390, we get 3 with a remainder of 345.
The next digit of our result is 3. 
Result so far: 33023.0
Subtract 1170 from 1515 to get 345.
Since there are no more digits in the dividend, we add a zero to the remainder making it 3450, and continue the process.

Advancing to step 9:
390 can be fit into 3450 8 times, resulting in a remainder of 330.
Put 8 as the next digit of the answer. 
Result so far: 33023.8
Deduct 3120 from 3450 and we're left 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.

Moving on to step 10:
When dividing 3300 by 390, we get 8 with a remainder of 180.
The next digit of our result is 8. 
Result so far: 33023.88
The remainder is 180 after subtracting 3120 from 3300.
Since there are no more digits in the dividend, we add a zero to the remainder making it 1800, and continue the process.

The final result is 33023.88 with a remainder of 0.18.