87169975 divided by 643 
The aim is to understand the frequency of 643 in 87169975.

Going ahead to step 1:
The number 643 fits into 8 0 times, leaving a remainder of 8.
The number 0 becomes the next digit in our result. 
Result so far: 0.0
Subtracting 0 from 8 leaves us with 8.
Fetch the next digit (7) from the dividend, attach it to 8 and continue: 87 / 643

Moving on to step 2:
87 divided by 643 is 0 with a remainder of 87.
Use 0 as the next digit of our solution. 
Result so far: 0.0
If we take 0 away from 87, we end up with 87.
Bring next digit (1) of the dividend behind the 87 and repeat the process: 871 / 643

Going ahead to step 3:
871 divided by 643 is 1 with a remainder of 228.
Record the quotient 1 as the next digit in the result. 
Result so far: 1.0
Deduct 643 from 871 and we're left with 228.
Take the next digit (6) from the dividend and append it to 228, then repeat: 2286 / 643

Going ahead to step 4:
When dividing 2286 by 643, we get 3 with a remainder of 357.
The number 3 becomes the next digit in our result. 
Result so far: 13.0
If we subtract 1929 from 2286, we get 357.
Append the next digit (9) from the dividend to 357 and continue with: 3579 / 643

Advancing to step 5:
3579 divided by 643 is 5 with a remainder of 364.
The next digit of our result is 5. 
Result so far: 135.0
Deduct 3215 from 3579 and we're left with 364.
Fetch the next digit (9) from the dividend, attach it to 364 and continue: 3649 / 643

Step 6:
If we divide 3649 by 643, we get 5 and a remainder of 434.
Put 5 as the next digit of the answer. 
Result so far: 1355.0
If we take 3215 away from 3649, we end up with 434.
Fetch the next digit (7) from the dividend, attach it to 434 and continue: 4347 / 643

Step 7:
4347 divided by 643 is 6 with a remainder of 489.
Write down 6 as next digit of the result. 
Result so far: 13556.0
If we take 3858 away from 4347, we end up with 489.
Take the next digit (5) from the dividend and append it to 489, then repeat: 4895 / 643

Let's proceed to step 8:
4895 divided by 643 is 7 with a remainder of 394.
Use 7 as the next digit of our solution. 
Result so far: 135567.0
If we subtract 4501 from 4895, we get 394.
Since there are no more digits in the dividend, we add a zero to the remainder making it 3940, and continue the process.

On to step 9:
When dividing 3940 by 643, we get 6 with a remainder of 82.
Use 6 as the next digit of our solution. 
Result so far: 135567.6
Deduct 3858 from 3940 and we're left with 82.
Since there are no more digits in the dividend, we add a zero to the remainder making it 820, and continue the process.

Advancing to step 10:
643 can be fit into 820 1 times, resulting in a remainder of 177.
Record the quotient 1 as the next digit in the result. 
Result so far: 135567.61
Subtract 643 from 820 to get 177.
Since there are no more digits in the dividend, we add a zero to the remainder making it 1770, and continue the process.

Going ahead to step 11:
The number 643 fits into 1770 2 times, leaving a remainder of 484.
Put 2 as the next digit of the answer. 
Result so far: 135567.612
If we take 1286 away from 1770, we end up with 484.
Since there are no more digits in the dividend, we add a zero to the remainder making it 4840, and continue the process.

Moving on to step 12:
The number 643 fits into 4840 7 times, leaving a remainder of 339.
Write down 7 as next digit of the result. 
Result so far: 135567.6127
If we subtract 4501 from 4840, we get 339.
Since there are no more digits in the dividend, we add a zero to the remainder making it 3390, and continue the process.

Let's proceed to step 13:
When dividing 3390 by 643, we get 5 with a remainder of 175.
The next digit of our result is 5. 
Result so far: 135567.61275
Subtracting 3215 from 3390 leaves us with 175.
Since there are no more digits in the dividend, we add a zero to the remainder making it 1750, and continue the process.

Step 14:
643 can be fit into 1750 2 times, resulting in a remainder of 464.
Use 2 as the next digit of our solution. 
Result so far: 135567.612752
If we subtract 1286 from 1750, we get 464.
Since there are no more digits in the dividend, we add a zero to the remainder making it 4640, and continue the process.

Let's proceed to step 15:
4640 divided by 643 is 7 with a remainder of 139.
Use 7 as the next digit of our solution. 
Result so far: 135567.6127527
Subtract 4501 from 4640 to get 139.
Since there are no more digits in the dividend, we add a zero to the remainder making it 1390, and continue the process.

Moving on to step 16:
1390 divided by 643 is 2 with a remainder of 104.
Use 2 as the next digit of our solution. 
Result so far: 135567.61275272
The remainder is 104 after subtracting 1286 from 1390.
Since there are no more digits in the dividend, we add a zero to the remainder making it 1040, and continue the process.

In conclusion, the division gives 135567.61275272 with a balance of 1.04e-07.