We look at the division of 66359261 by 878 
The aim is to understand the frequency of 878 in 66359261.

Let's proceed to step 1:
878 can be fit into 6 0 times, resulting in a remainder of 6.
The number 0 becomes the next digit in our result. 
Result so far: 0.0
If we subtract 0 from 6, we get 6.
Fetch the next digit (6) from the dividend, attach it to 6 and continue: 66 / 878

On to step 2:
878 goes into 66 0 times with a remainder of 66.
Write down 0 as next digit of the result. 
Result so far: 0.0
The remainder is 66 after subtracting 0 from 66.
Take the next digit (3) from the dividend and append it to 66, then repeat: 663 / 878

Advancing to step 3:
When dividing 663 by 878, we get 0 with a remainder of 663.
Put 0 as the next digit of the answer. 
Result so far: 0.0
Subtracting 0 from 663 leaves us with 663.
Append the next digit (5) from the dividend to 663 and continue with: 6635 / 878

Let's proceed to step 4:
878 goes into 6635 7 times with a remainder of 489.
Use 7 as the next digit of our solution. 
Result so far: 7.0
Subtract 6146 from 6635 to get 489.
Bring next digit (9) of the dividend behind the 489 and repeat the process: 4899 / 878

Moving on to step 5:
When dividing 4899 by 878, we get 5 with a remainder of 509.
Record the quotient 5 as the next digit in the result. 
Result so far: 75.0
Subtract 4390 from 4899 to get 509.
Bring next digit (2) of the dividend behind the 509 and repeat the process: 5092 / 878

Let's proceed to step 6:
878 goes into 5092 5 times with a remainder of 702.
Put 5 as the next digit of the answer. 
Result so far: 755.0
Subtract 4390 from 5092 to get 702.
Append the next digit (6) from the dividend to 702 and continue with: 7026 / 878

Moving on to step 7:
7026 divided by 878 is 8 with a remainder of 2.
The next digit of our result is 8. 
Result so far: 7558.0
The remainder is 2 after subtracting 7024 from 7026.
Take the next digit (1) from the dividend and append it to 2, then repeat: 21 / 878

Moving on to step 8:
The number 878 fits into 21 0 times, leaving a remainder of 21.
Record the quotient 0 as the next digit in the result. 
Result so far: 75580.0
If we take 0 away from 21, we end up with 21.
Since there are no more digits in the dividend, we add a zero to the remainder making it 210, and continue the process.

Moving on to step 9:
210 divided by 878 is 0 with a remainder of 210.
Use 0 as the next digit of our solution. 
Result so far: 75580.0
Subtract 0 from 210 to get 210.
Since there are no more digits in the dividend, we add a zero to the remainder making it 2100, and continue the process.

On to step 10:
878 goes into 2100 2 times with a remainder of 344.
Put 2 as the next digit of the answer. 
Result so far: 75580.02
Deduct 1756 from 2100 and we're left with 344.
Since there are no more digits in the dividend, we add a zero to the remainder making it 3440, and continue the process.

On to step 11:
878 goes into 3440 3 times with a remainder of 806.
Put 3 as the next digit of the answer. 
Result so far: 75580.023
The remainder is 806 after subtracting 2634 from 3440.
Since there are no more digits in the dividend, we add a zero to the remainder making it 8060, and continue the process.

Moving on to step 12:
The number 878 fits into 8060 9 times, leaving a remainder of 158.
Write down 9 as next digit of the result. 
Result so far: 75580.0239
The remainder is 158 after subtracting 7902 from 8060.
Since there are no more digits in the dividend, we add a zero to the remainder making it 1580, and continue the process.

Let's proceed to step 13:
If we divide 1580 by 878, we get 1 and a remainder of 702.
Use 1 as the next digit of our solution. 
Result so far: 75580.02391
Subtracting 878 from 1580 leaves us with 702.
Since there are no more digits in the dividend, we add a zero to the remainder making it 7020, and continue the process.

Let's proceed to step 14:
If we divide 7020 by 878, we get 7 and a remainder of 874.
Use 7 as the next digit of our solution. 
Result so far: 75580.023917
The remainder is 874 after subtracting 6146 from 7020.
Since there are no more digits in the dividend, we add a zero to the remainder making it 8740, and continue the process.

Advancing to step 15:
878 goes into 8740 9 times with a remainder of 838.
Use 9 as the next digit of our solution. 
Result so far: 75580.0239179
Deduct 7902 from 8740 and we're left with 838.
Since there are no more digits in the dividend, we add a zero to the remainder making it 8380, and continue the process.

On to step 16:
8380 divided by 878 is 9 with a remainder of 478.
The number 9 becomes the next digit in our result. 
Result so far: 75580.02391799
If we take 7902 away from 8380, we end up with 478.
Since there are no more digits in the dividend, we add a zero to the remainder making it 4780, and continue the process.

After the division, we end up with 75580.02391799 and a remainder of 4.78e-07.