61397829 ÷ 815 
The aim is to understand the frequency of 815 in 61397829.

Step 1:
When dividing 6 by 815, we get 0 with a remainder of 6.
Use 0 as the next digit of our solution. 
Result so far: 0.0
Deduct 0 from 6 and we're left with 6.
Bring next digit (1) of the dividend behind the 6 and repeat the process: 61 / 815

Advancing to step 2:
815 goes into 61 0 times with a remainder of 61.
The number 0 becomes the next digit in our result. 
Result so far: 0.0
Subtract 0 from 61 to get 61.
Fetch the next digit (3) from the dividend, attach it to 61 and continue: 613 / 815

Step 3:
The number 815 fits into 613 0 times, leaving a remainder of 613.
Record the quotient 0 as the next digit in the result. 
Result so far: 0.0
Subtracting 0 from 613 leaves us with 613.
Include the next digit (9) from the dividend after 613, then repeat: 6139 / 815

Advancing to step 4:
815 can be fit into 6139 7 times, resulting in a remainder of 434.
Record the quotient 7 as the next digit in the result. 
Result so far: 7.0
Subtract 5705 from 6139 to get 434.
Fetch the next digit (7) from the dividend, attach it to 434 and continue: 4347 / 815

Step 5:
4347 divided by 815 is 5 with a remainder of 272.
Record the quotient 5 as the next digit in the result. 
Result so far: 75.0
If we take 4075 away from 4347, we end up with 272.
Take the next digit (8) from the dividend and append it to 272, then repeat: 2728 / 815

Step 6:
When dividing 2728 by 815, we get 3 with a remainder of 283.
Write down 3 as next digit of the result. 
Result so far: 753.0
If we subtract 2445 from 2728, we get 283.
Take the next digit (2) from the dividend and append it to 283, then repeat: 2832 / 815

Step 7:
815 can be fit into 2832 3 times, resulting in a remainder of 387.
Record the quotient 3 as the next digit in the result. 
Result so far: 7533.0
Deduct 2445 from 2832 and we're left with 387.
Bring next digit (9) of the dividend behind the 387 and repeat the process: 3879 / 815

On to step 8:
3879 divided by 815 is 4 with a remainder of 619.
Write down 4 as next digit of the result. 
Result so far: 75334.0
The remainder is 619 after subtracting 3260 from 3879.
Since there are no more digits in the dividend, we add a zero to the remainder making it 6190, and continue the process.

Going ahead to step 9:
815 can be fit into 6190 7 times, resulting in a remainder of 485.
The number 7 becomes the next digit in our result. 
Result so far: 75334.7
Subtracting 5705 from 6190 leaves us with 485.
Since there are no more digits in the dividend, we add a zero to the remainder making it 4850, and continue the process.

Advancing to step 10:
If we divide 4850 by 815, we get 5 and a remainder of 775.
Record the quotient 5 as the next digit in the result. 
Result so far: 75334.75
Subtract 4075 from 4850 to get 775.
Since there are no more digits in the dividend, we add a zero to the remainder making it 7750, and continue the process.

Advancing to step 11:
7750 divided by 815 is 9 with a remainder of 415.
Record the quotient 9 as the next digit in the result. 
Result so far: 75334.759
The remainder is 415 after subtracting 7335 from 7750.
Since there are no more digits in the dividend, we add a zero to the remainder making it 4150, and continue the process.

Going ahead to step 12:
4150 divided by 815 is 5 with a remainder of 75.
The next digit of our result is 5. 
Result so far: 75334.7595
The remainder is 75 after subtracting 4075 from 4150.
Since there are no more digits in the dividend, we add a zero to the remainder making it 750, and continue the process.

Advancing to step 13:
If we divide 750 by 815, we get 0 and a remainder of 750.
Write down 0 as next digit of the result. 
Result so far: 75334.7595
If we subtract 0 from 750, we get 750.
Since there are no more digits in the dividend, we add a zero to the remainder making it 7500, and continue the process.

Going ahead to step 14:
7500 divided by 815 is 9 with a remainder of 165.
The number 9 becomes the next digit in our result. 
Result so far: 75334.759509
Deduct 7335 from 7500 and we're left with 165.
Since there are no more digits in the dividend, we add a zero to the remainder making it 1650, and continue the process.

Advancing to step 15:
If we divide 1650 by 815, we get 2 and a remainder of 20.
Put 2 as the next digit of the answer. 
Result so far: 75334.7595092
Subtract 1630 from 1650 to get 20.
Since there are no more digits in the dividend, we add a zero to the remainder making it 200, and continue the process.

Let's proceed to step 16:
815 goes into 200 0 times with a remainder of 200.
Put 0 as the next digit of the answer. 
Result so far: 75334.7595092
If we subtract 0 from 200, we get 200.
Since there are no more digits in the dividend, we add a zero to the remainder making it 2000, and continue the process.

The final result is 75334.7595092 with a remainder of 2e-07.