We're dividing 86699631 by 629 
The aim is to understand the frequency of 629 in 86699631.

On to step 1:
When dividing 8 by 629, we get 0 with a remainder of 8.
Put 0 as the next digit of the answer. 
Result so far: 0.0
If we subtract 0 from 8, we get 8.
Grab the next digit (6) from the dividend, add it to 8, then carry on: 86 / 629

Step 2:
629 can be fit into 86 0 times, resulting in a remainder of 86.
Record the quotient 0 as the next digit in the result. 
Result so far: 0.0
Deduct 0 from 86 and we're left with 86.
Fetch the next digit (6) from the dividend, attach it to 86 and continue: 866 / 629

Moving on to step 3:
The number 629 fits into 866 1 times, leaving a remainder of 237.
Use 1 as the next digit of our solution. 
Result so far: 1.0
If we take 629 away from 866, we end up with 237.
Include the next digit (9) from the dividend after 237, then repeat: 2379 / 629

Moving on to step 4:
When dividing 2379 by 629, we get 3 with a remainder of 492.
Record the quotient 3 as the next digit in the result. 
Result so far: 13.0
Subtracting 1887 from 2379 leaves us with 492.
Take the next digit (9) from the dividend and append it to 492, then repeat: 4929 / 629

Step 5:
629 can be fit into 4929 7 times, resulting in a remainder of 526.
Put 7 as the next digit of the answer. 
Result so far: 137.0
Subtracting 4403 from 4929 leaves us with 526.
Grab the next digit (6) from the dividend, add it to 526, then carry on: 5266 / 629

Moving on to step 6:
629 can be fit into 5266 8 times, resulting in a remainder of 234.
The next digit of our result is 8. 
Result so far: 1378.0
Subtract 5032 from 5266 to get 234.
Fetch the next digit (3) from the dividend, attach it to 234 and continue: 2343 / 629

On to step 7:
The number 629 fits into 2343 3 times, leaving a remainder of 456.
The number 3 becomes the next digit in our result. 
Result so far: 13783.0
If we take 1887 away from 2343, we end up with 456.
Fetch the next digit (1) from the dividend, attach it to 456 and continue: 4561 / 629

Step 8:
If we divide 4561 by 629, we get 7 and a remainder of 158.
Write down 7 as next digit of the result. 
Result so far: 137837.0
If we take 4403 away from 4561, we end up with 158.
Since there are no more digits in the dividend, we add a zero to the remainder making it 1580, and continue the process.

On to step 9:
629 can be fit into 1580 2 times, resulting in a remainder of 322.
Put 2 as the next digit of the answer. 
Result so far: 137837.2
If we subtract 1258 from 1580, we get 322.
Since there are no more digits in the dividend, we add a zero to the remainder making it 3220, and continue the process.

Advancing to step 10:
When dividing 3220 by 629, we get 5 with a remainder of 75.
Use 5 as the next digit of our solution. 
Result so far: 137837.25
Subtracting 3145 from 3220 leaves us with 75.
Since there are no more digits in the dividend, we add a zero to the remainder making it 750, and continue the process.

Step 11:
629 goes into 750 1 times with a remainder of 121.
Put 1 as the next digit of the answer. 
Result so far: 137837.251
If we take 629 away from 750, we end up with 121.
Since there are no more digits in the dividend, we add a zero to the remainder making it 1210, and continue the process.

Let's proceed to step 12:
The number 629 fits into 1210 1 times, leaving a remainder of 581.
Record the quotient 1 as the next digit in the result. 
Result so far: 137837.2511
Subtract 629 from 1210 to get 581.
Since there are no more digits in the dividend, we add a zero to the remainder making it 5810, and continue the process.

The final result is 137837.2511 with a remainder of 0.00581.