We look at the division of 99109451 by 631 
The aim is to understand the frequency of 631 in 99109451.

Step 1:
If we divide 9 by 631, we get 0 and a remainder of 9.
Use 0 as the next digit of our solution. 
Result so far: 0.0
If we take 0 away from 9, we end up with 9.
Append the next digit (9) from the dividend to 9 and continue with: 99 / 631

Going ahead to step 2:
When dividing 99 by 631, we get 0 with a remainder of 99.
Write down 0 as next digit of the result. 
Result so far: 0.0
Deduct 0 from 99 and we're left with 99.
Bring next digit (1) of the dividend behind the 99 and repeat the process: 991 / 631

Moving on to step 3:
When dividing 991 by 631, we get 1 with a remainder of 360.
Put 1 as the next digit of the answer. 
Result so far: 1.0
If we subtract 631 from 991, we get 360.
Append the next digit (0) from the dividend to 360 and continue with: 3600 / 631

Let's proceed to step 4:
The number 631 fits into 3600 5 times, leaving a remainder of 445.
The number 5 becomes the next digit in our result. 
Result so far: 15.0
If we take 3155 away from 3600, we end up with 445.
Grab the next digit (9) from the dividend, add it to 445, then carry on: 4459 / 631

Advancing to step 5:
631 can be fit into 4459 7 times, resulting in a remainder of 42.
Put 7 as the next digit of the answer. 
Result so far: 157.0
The remainder is 42 after subtracting 4417 from 4459.
Grab the next digit (4) from the dividend, add it to 42, then carry on: 424 / 631

Going ahead to step 6:
424 divided by 631 is 0 with a remainder of 424.
The number 0 becomes the next digit in our result. 
Result so far: 1570.0
Deduct 0 from 424 and we're left with 424.
Append the next digit (5) from the dividend to 424 and continue with: 4245 / 631

Step 7:
631 can be fit into 4245 6 times, resulting in a remainder of 459.
Use 6 as the next digit of our solution. 
Result so far: 15706.0
Subtracting 3786 from 4245 leaves us with 459.
Include the next digit (1) from the dividend after 459, then repeat: 4591 / 631

Moving on to step 8:
The number 631 fits into 4591 7 times, leaving a remainder of 174.
Write down 7 as next digit of the result. 
Result so far: 157067.0
The remainder is 174 after subtracting 4417 from 4591.
Since there are no more digits in the dividend, we add a zero to the remainder making it 1740, and continue the process.

Going ahead to step 9:
If we divide 1740 by 631, we get 2 and a remainder of 478.
Record the quotient 2 as the next digit in the result. 
Result so far: 157067.2
The remainder is 478 after subtracting 1262 from 1740.
Since there are no more digits in the dividend, we add a zero to the remainder making it 4780, and continue the process.

On to step 10:
631 goes into 4780 7 times with a remainder of 363.
Put 7 as the next digit of the answer. 
Result so far: 157067.27
Subtract 4417 from 4780 to get 363.
Since there are no more digits in the dividend, we add a zero to the remainder making it 3630, and continue the process.

On to step 11:
When dividing 3630 by 631, we get 5 with a remainder of 475.
Write down 5 as next digit of the result. 
Result so far: 157067.275
Subtracting 3155 from 3630 leaves us with 475.
Since there are no more digits in the dividend, we add a zero to the remainder making it 4750, and continue the process.

Let's proceed to step 12:
The number 631 fits into 4750 7 times, leaving a remainder of 333.
Put 7 as the next digit of the answer. 
Result so far: 157067.2757
If we take 4417 away from 4750, we end up with 333.
Since there are no more digits in the dividend, we add a zero to the remainder making it 3330, and continue the process.

Advancing to step 13:
631 can be fit into 3330 5 times, resulting in a remainder of 175.
Write down 5 as next digit of the result. 
Result so far: 157067.27575
The remainder is 175 after subtracting 3155 from 3330.
Since there are no more digits in the dividend, we add a zero to the remainder making it 1750, and continue the process.

On to step 14:
1750 divided by 631 is 2 with a remainder of 488.
Put 2 as the next digit of the answer. 
Result so far: 157067.275752
Deduct 1262 from 1750 and we're left with 488.
Since there are no more digits in the dividend, we add a zero to the remainder making it 4880, and continue the process.

Step 15:
631 goes into 4880 7 times with a remainder of 463.
The next digit of our result is 7. 
Result so far: 157067.2757527
If we subtract 4417 from 4880, we get 463.
Since there are no more digits in the dividend, we add a zero to the remainder making it 4630, and continue the process.

Let's proceed to step 16:
631 can be fit into 4630 7 times, resulting in a remainder of 213.
Put 7 as the next digit of the answer. 
Result so far: 157067.27575277
If we take 4417 away from 4630, we end up with 213.
Since there are no more digits in the dividend, we add a zero to the remainder making it 2130, and continue the process.

After the division, we end up with 157067.27575277 and a remainder of 2.13e-07.