We look at the division of 65820798 by 816 
The aim is to understand the frequency of 816 in 65820798.

On to step 1:
6 divided by 816 is 0 with 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.
Append the next digit (5) from the dividend to 6 and continue with: 65 / 816

Step 2:
When dividing 65 by 816, we get 0 with a remainder of 65.
Use 0 as the next digit of our solution. 
Result so far: 0.0
Subtract 0 from 65 to get 65.
Grab the next digit (8) from the dividend, add it to 65, then carry on: 658 / 816

Going ahead to step 3:
816 goes into 658 0 times with a remainder of 658.
Use 0 as the next digit of our solution. 
Result so far: 0.0
If we subtract 0 from 658, we get 658.
Grab the next digit (2) from the dividend, add it to 658, then carry on: 6582 / 816

On to step 4:
The number 816 fits into 6582 8 times, leaving a remainder of 54.
The number 8 becomes the next digit in our result. 
Result so far: 8.0
Subtract 6528 from 6582 to get 54.
Bring next digit (0) of the dividend behind the 54 and repeat the process: 540 / 816

On to step 5:
When dividing 540 by 816, we get 0 with a remainder of 540.
Write down 0 as next digit of the result. 
Result so far: 80.0
Deduct 0 from 540 and we're left with 540.
Bring next digit (7) of the dividend behind the 540 and repeat the process: 5407 / 816

Going ahead to step 6:
5407 divided by 816 is 6 with a remainder of 511.
Write down 6 as next digit of the result. 
Result so far: 806.0
Deduct 4896 from 5407 and we're left with 511.
Fetch the next digit (9) from the dividend, attach it to 511 and continue: 5119 / 816

On to step 7:
816 can be fit into 5119 6 times, resulting in a remainder of 223.
The next digit of our result is 6. 
Result so far: 8066.0
If we take 4896 away from 5119, we end up with 223.
Grab the next digit (8) from the dividend, add it to 223, then carry on: 2238 / 816

Going ahead to step 8:
The number 816 fits into 2238 2 times, leaving a remainder of 606.
Write down 2 as next digit of the result. 
Result so far: 80662.0
If we subtract 1632 from 2238, we get 606.
Since there are no more digits in the dividend, we add a zero to the remainder making it 6060, and continue the process.

On to step 9:
When dividing 6060 by 816, we get 7 with a remainder of 348.
Use 7 as the next digit of our solution. 
Result so far: 80662.7
Deduct 5712 from 6060 and we're left with 348.
Since there are no more digits in the dividend, we add a zero to the remainder making it 3480, and continue the process.

Advancing to step 10:
816 goes into 3480 4 times with a remainder of 216.
Record the quotient 4 as the next digit in the result. 
Result so far: 80662.74
Subtract 3264 from 3480 to get 216.
Since there are no more digits in the dividend, we add a zero to the remainder making it 2160, and continue the process.

On to step 11:
816 can be fit into 2160 2 times, resulting in a remainder of 528.
The number 2 becomes the next digit in our result. 
Result so far: 80662.742
Subtracting 1632 from 2160 leaves us with 528.
Since there are no more digits in the dividend, we add a zero to the remainder making it 5280, and continue the process.

On to step 12:
816 goes into 5280 6 times with a remainder of 384.
The next digit of our result is 6. 
Result so far: 80662.7426
Deduct 4896 from 5280 and we're left with 384.
Since there are no more digits in the dividend, we add a zero to the remainder making it 3840, and continue the process.

Step 13:
816 can be fit into 3840 4 times, resulting in a remainder of 576.
Use 4 as the next digit of our solution. 
Result so far: 80662.74264
If we take 3264 away from 3840, we end up with 576.
Since there are no more digits in the dividend, we add a zero to the remainder making it 5760, and continue the process.

Going ahead to step 14:
5760 divided by 816 is 7 with a remainder of 48.
The next digit of our result is 7. 
Result so far: 80662.742647
Subtracting 5712 from 5760 leaves us with 48.
Since there are no more digits in the dividend, we add a zero to the remainder making it 480, and continue the process.

Step 15:
If we divide 480 by 816, we get 0 and a remainder of 480.
Put 0 as the next digit of the answer. 
Result so far: 80662.742647
Subtract 0 from 480 to get 480.
Since there are no more digits in the dividend, we add a zero to the remainder making it 4800, and continue the process.

Let's proceed to step 16:
The number 816 fits into 4800 5 times, leaving a remainder of 720.
Put 5 as the next digit of the answer. 
Result so far: 80662.74264705
Deduct 4080 from 4800 and we're left with 720.
Since there are no more digits in the dividend, we add a zero to the remainder making it 7200, and continue the process.

The final outcome is 80662.74264705, with a leftover of 7.2e-07.