We're dividing 12878783 by 870 
The aim is to understand the frequency of 870 in 12878783.

Step 1:
When dividing 1 by 870, we get 0 with a remainder of 1.
Put 0 as the next digit of the answer. 
Result so far: 0.0
Deduct 0 from 1 and we're left with 1.
Bring next digit (2) of the dividend behind the 1 and repeat the process: 12 / 870

Advancing to step 2:
870 can be fit into 12 0 times, resulting in a remainder of 12.
Use 0 as the next digit of our solution. 
Result so far: 0.0
The remainder is 12 after subtracting 0 from 12.
Fetch the next digit (8) from the dividend, attach it to 12 and continue: 128 / 870

Advancing to step 3:
870 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
Subtracting 0 from 128 leaves us with 128.
Bring next digit (7) of the dividend behind the 128 and repeat the process: 1287 / 870

Let's proceed to step 4:
1287 divided by 870 is 1 with a remainder of 417.
Use 1 as the next digit of our solution. 
Result so far: 1.0
Subtract 870 from 1287 to get 417.
Include the next digit (8) from the dividend after 417, then repeat: 4178 / 870

Step 5:
If we divide 4178 by 870, we get 4 and a remainder of 698.
The number 4 becomes the next digit in our result. 
Result so far: 14.0
If we subtract 3480 from 4178, we get 698.
Bring next digit (7) of the dividend behind the 698 and repeat the process: 6987 / 870

Step 6:
If we divide 6987 by 870, we get 8 and a remainder of 27.
Record the quotient 8 as the next digit in the result. 
Result so far: 148.0
Deduct 6960 from 6987 and we're left with 27.
Bring next digit (8) of the dividend behind the 27 and repeat the process: 278 / 870

Moving on to step 7:
When dividing 278 by 870, we get 0 with a remainder of 278.
Record the quotient 0 as the next digit in the result. 
Result so far: 1480.0
The remainder is 278 after subtracting 0 from 278.
Include the next digit (3) from the dividend after 278, then repeat: 2783 / 870

Going ahead to step 8:
The number 870 fits into 2783 3 times, leaving a remainder of 173.
Use 3 as the next digit of our solution. 
Result so far: 14803.0
Subtracting 2610 from 2783 leaves us with 173.
Since there are no more digits in the dividend, we add a zero to the remainder making it 1730, and continue the process.

Moving on to step 9:
When dividing 1730 by 870, we get 1 with a remainder of 860.
Put 1 as the next digit of the answer. 
Result so far: 14803.1
Subtracting 870 from 1730 leaves us with 860.
Since there are no more digits in the dividend, we add a zero to the remainder making it 8600, and continue the process.

Step 10:
If we divide 8600 by 870, we get 9 and a remainder of 770.
Write down 9 as next digit of the result. 
Result so far: 14803.19
Subtracting 7830 from 8600 leaves us with 770.
Since there are no more digits in the dividend, we add a zero to the remainder making it 7700, and continue the process.

Advancing to step 11:
When dividing 7700 by 870, we get 8 with a remainder of 740.
Put 8 as the next digit of the answer. 
Result so far: 14803.198
Subtract 6960 from 7700 to get 740.
Since there are no more digits in the dividend, we add a zero to the remainder making it 7400, and continue the process.

Step 12:
If we divide 7400 by 870, we get 8 and a remainder of 440.
The next digit of our result is 8. 
Result so far: 14803.1988
If we take 6960 away from 7400, we end up with 440.
Since there are no more digits in the dividend, we add a zero to the remainder making it 4400, and continue the process.

Our division results in 14803.1988 with a remaining 0.0044.