We're dividing 86136679 by 644 
The aim is to understand the frequency of 644 in 86136679.

Advancing to step 1:
When dividing 8 by 644, we get 0 with a remainder of 8.
Use 0 as the next digit of our solution. 
Result so far: 0.0
The remainder is 8 after subtracting 0 from 8.
Bring next digit (6) of the dividend behind the 8 and repeat the process: 86 / 644

Moving on to step 2:
If we divide 86 by 644, we get 0 and a remainder of 86.
Put 0 as the next digit of the answer. 
Result so far: 0.0
Deduct 0 from 86 and we're left with 86.
Include the next digit (1) from the dividend after 86, then repeat: 861 / 644

Going ahead to step 3:
When dividing 861 by 644, we get 1 with a remainder of 217.
Put 1 as the next digit of the answer. 
Result so far: 1.0
If we subtract 644 from 861, we get 217.
Bring next digit (3) of the dividend behind the 217 and repeat the process: 2173 / 644

On to step 4:
When dividing 2173 by 644, we get 3 with a remainder of 241.
Use 3 as the next digit of our solution. 
Result so far: 13.0
Subtract 1932 from 2173 to get 241.
Grab the next digit (6) from the dividend, add it to 241, then carry on: 2416 / 644

Advancing to step 5:
2416 divided by 644 is 3 with a remainder of 484.
The number 3 becomes the next digit in our result. 
Result so far: 133.0
Subtract 1932 from 2416 to get 484.
Grab the next digit (6) from the dividend, add it to 484, then carry on: 4846 / 644

Going ahead to step 6:
When dividing 4846 by 644, we get 7 with a remainder of 338.
Write down 7 as next digit of the result. 
Result so far: 1337.0
The remainder is 338 after subtracting 4508 from 4846.
Fetch the next digit (7) from the dividend, attach it to 338 and continue: 3387 / 644

Going ahead to step 7:
The number 644 fits into 3387 5 times, leaving a remainder of 167.
Record the quotient 5 as the next digit in the result. 
Result so far: 13375.0
The remainder is 167 after subtracting 3220 from 3387.
Append the next digit (9) from the dividend to 167 and continue with: 1679 / 644

Step 8:
644 can be fit into 1679 2 times, resulting in a remainder of 391.
The number 2 becomes the next digit in our result. 
Result so far: 133752.0
Subtracting 1288 from 1679 leaves us with 391.
Since there are no more digits in the dividend, we add a zero to the remainder making it 3910, and continue the process.

Going ahead to step 9:
If we divide 3910 by 644, we get 6 and a remainder of 46.
The next digit of our result is 6. 
Result so far: 133752.6
Deduct 3864 from 3910 and we're left with 46.
Since there are no more digits in the dividend, we add a zero to the remainder making it 460, and continue the process.

Step 10:
If we divide 460 by 644, we get 0 and a remainder of 460.
Put 0 as the next digit of the answer. 
Result so far: 133752.6
If we subtract 0 from 460, we get 460.
Since there are no more digits in the dividend, we add a zero to the remainder making it 4600, and continue the process.

Going ahead to step 11:
644 can be fit into 4600 7 times, resulting in a remainder of 92.
Record the quotient 7 as the next digit in the result. 
Result so far: 133752.607
Subtract 4508 from 4600 to get 92.
Since there are no more digits in the dividend, we add a zero to the remainder making it 920, and continue the process.

Going ahead to step 12:
644 goes into 920 1 times with a remainder of 276.
Record the quotient 1 as the next digit in the result. 
Result so far: 133752.6071
If we take 644 away from 920, we end up with 276.
Since there are no more digits in the dividend, we add a zero to the remainder making it 2760, and continue the process.

On to step 13:
When dividing 2760 by 644, we get 4 with a remainder of 184.
The number 4 becomes the next digit in our result. 
Result so far: 133752.60714
If we take 2576 away from 2760, we end up with 184.
Since there are no more digits in the dividend, we add a zero to the remainder making it 1840, and continue the process.

Advancing to step 14:
If we divide 1840 by 644, we get 2 and a remainder of 552.
Put 2 as the next digit of the answer. 
Result so far: 133752.607142
Subtract 1288 from 1840 to get 552.
Since there are no more digits in the dividend, we add a zero to the remainder making it 5520, and continue the process.

On to step 15:
5520 divided by 644 is 8 with a remainder of 368.
Put 8 as the next digit of the answer. 
Result so far: 133752.6071428
Deduct 5152 from 5520 and we're left with 368.
Since there are no more digits in the dividend, we add a zero to the remainder making it 3680, and continue the process.

Going ahead to step 16:
If we divide 3680 by 644, we get 5 and a remainder of 460.
Put 5 as the next digit of the answer. 
Result so far: 133752.60714285
The remainder is 460 after subtracting 3220 from 3680.
Since there are no more digits in the dividend, we add a zero to the remainder making it 4600, and continue the process.

The quotient of the division is 133752.60714285, and the remainder is 4.6e-07.