83781429 divided by 641 
The aim is to understand the frequency of 641 in 83781429.

Step 1:
If we divide 8 by 641, we get 0 and a remainder of 8.
The number 0 becomes the next digit in our result. 
Result so far: 0.0
If we subtract 0 from 8, we get 8.
Include the next digit (3) from the dividend after 8, then repeat: 83 / 641

Step 2:
641 can be fit into 83 0 times, resulting in a remainder of 83.
The number 0 becomes the next digit in our result. 
Result so far: 0.0
Subtracting 0 from 83 leaves us with 83.
Append the next digit (7) from the dividend to 83 and continue with: 837 / 641

On to step 3:
If we divide 837 by 641, we get 1 and a remainder of 196.
Use 1 as the next digit of our solution. 
Result so far: 1.0
If we subtract 641 from 837, we get 196.
Append the next digit (8) from the dividend to 196 and continue with: 1968 / 641

On to step 4:
When dividing 1968 by 641, we get 3 with a remainder of 45.
Record the quotient 3 as the next digit in the result. 
Result so far: 13.0
The remainder is 45 after subtracting 1923 from 1968.
Grab the next digit (1) from the dividend, add it to 45, then carry on: 451 / 641

On to step 5:
641 can be fit into 451 0 times, resulting in a remainder of 451.
The number 0 becomes the next digit in our result. 
Result so far: 130.0
The remainder is 451 after subtracting 0 from 451.
Append the next digit (4) from the dividend to 451 and continue with: 4514 / 641

Moving on to step 6:
641 goes into 4514 7 times with a remainder of 27.
Put 7 as the next digit of the answer. 
Result so far: 1307.0
Subtract 4487 from 4514 to get 27.
Bring next digit (2) of the dividend behind the 27 and repeat the process: 272 / 641

Step 7:
If we divide 272 by 641, we get 0 and a remainder of 272.
Record the quotient 0 as the next digit in the result. 
Result so far: 13070.0
If we subtract 0 from 272, we get 272.
Fetch the next digit (9) from the dividend, attach it to 272 and continue: 2729 / 641

Moving on to step 8:
The number 641 fits into 2729 4 times, leaving a remainder of 165.
Put 4 as the next digit of the answer. 
Result so far: 130704.0
Subtract 2564 from 2729 to get 165.
Since there are no more digits in the dividend, we add a zero to the remainder making it 1650, and continue the process.

Let's proceed to step 9:
The number 641 fits into 1650 2 times, leaving a remainder of 368.
Put 2 as the next digit of the answer. 
Result so far: 130704.2
Subtracting 1282 from 1650 leaves us 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.

Advancing to step 10:
641 can be fit into 3680 5 times, resulting in a remainder of 475.
Use 5 as the next digit of our solution. 
Result so far: 130704.25
Deduct 3205 from 3680 and we're left 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.

Moving on to step 11:
The number 641 fits into 4750 7 times, leaving a remainder of 263.
Write down 7 as next digit of the result. 
Result so far: 130704.257
If we subtract 4487 from 4750, we get 263.
Since there are no more digits in the dividend, we add a zero to the remainder making it 2630, and continue the process.

Advancing to step 12:
641 goes into 2630 4 times with a remainder of 66.
Use 4 as the next digit of our solution. 
Result so far: 130704.2574
If we take 2564 away from 2630, we end up with 66.
Since there are no more digits in the dividend, we add a zero to the remainder making it 660, and continue the process.

Going ahead to step 13:
The number 641 fits into 660 1 times, leaving a remainder of 19.
Put 1 as the next digit of the answer. 
Result so far: 130704.25741
If we take 641 away from 660, we end up with 19.
Since there are no more digits in the dividend, we add a zero to the remainder making it 190, and continue the process.

Let's proceed to step 14:
641 can be fit into 190 0 times, resulting in a remainder of 190.
The next digit of our result is 0. 
Result so far: 130704.25741
Subtract 0 from 190 to get 190.
Since there are no more digits in the dividend, we add a zero to the remainder making it 1900, and continue the process.

Moving on to step 15:
The number 641 fits into 1900 2 times, leaving a remainder of 618.
The number 2 becomes the next digit in our result. 
Result so far: 130704.2574102
Subtracting 1282 from 1900 leaves us with 618.
Since there are no more digits in the dividend, we add a zero to the remainder making it 6180, and continue the process.

On to step 16:
If we divide 6180 by 641, we get 9 and a remainder of 411.
Use 9 as the next digit of our solution. 
Result so far: 130704.25741029
If we subtract 5769 from 6180, we get 411.
Since there are no more digits in the dividend, we add a zero to the remainder making it 4110, and continue the process.

The final result is 130704.25741029 with a remainder of 4.11e-07.