Let's divide 90090881 by 643
The aim is to understand the frequency of 643 in 90090881.

Moving on to step 1:
9 divided by 643 is 0 with a remainder of 9.
Write down 0 as next digit of the result. 
Result so far: 0.0
The remainder is 9 after subtracting 0 from 9.
Fetch the next digit (0) from the dividend, attach it to 9 and continue: 90 / 643

On to step 2:
643 goes into 90 0 times with a remainder of 90.
Put 0 as the next digit of the answer. 
Result so far: 0.0
If we take 0 away from 90, we end up with 90.
Take the next digit (0) from the dividend and append it to 90, then repeat: 900 / 643

Let's proceed to step 3:
The number 643 fits into 900 1 times, leaving a remainder of 257.
Write down 1 as next digit of the result. 
Result so far: 1.0
If we subtract 643 from 900, we get 257.
Include the next digit (9) from the dividend after 257, then repeat: 2579 / 643

Step 4:
If we divide 2579 by 643, we get 4 and a remainder of 7.
Record the quotient 4 as the next digit in the result. 
Result so far: 14.0
Deduct 2572 from 2579 and we're left with 7.
Append the next digit (0) from the dividend to 7 and continue with: 70 / 643

Let's proceed to step 5:
The number 643 fits into 70 0 times, leaving a remainder of 70.
Put 0 as the next digit of the answer. 
Result so far: 140.0
If we take 0 away from 70, we end up with 70.
Append the next digit (8) from the dividend to 70 and continue with: 708 / 643

Going ahead to step 6:
643 can be fit into 708 1 times, resulting in a remainder of 65.
The next digit of our result is 1. 
Result so far: 1401.0
If we take 643 away from 708, we end up with 65.
Append the next digit (8) from the dividend to 65 and continue with: 658 / 643

Step 7:
If we divide 658 by 643, we get 1 and a remainder of 15.
Put 1 as the next digit of the answer. 
Result so far: 14011.0
The remainder is 15 after subtracting 643 from 658.
Fetch the next digit (1) from the dividend, attach it to 15 and continue: 151 / 643

On to step 8:
643 can be fit into 151 0 times, resulting in a remainder of 151.
Use 0 as the next digit of our solution. 
Result so far: 140110.0
Subtract 0 from 151 to get 151.
Since there are no more digits in the dividend, we add a zero to the remainder making it 1510, and continue the process.

Let's proceed to step 9:
If we divide 1510 by 643, we get 2 and a remainder of 224.
Use 2 as the next digit of our solution. 
Result so far: 140110.2
Subtract 1286 from 1510 to get 224.
Since there are no more digits in the dividend, we add a zero to the remainder making it 2240, and continue the process.

Let's proceed to step 10:
The number 643 fits into 2240 3 times, leaving a remainder of 311.
Put 3 as the next digit of the answer. 
Result so far: 140110.23
Deduct 1929 from 2240 and we're left with 311.
Since there are no more digits in the dividend, we add a zero to the remainder making it 3110, and continue the process.

Moving on to step 11:
If we divide 3110 by 643, we get 4 and a remainder of 538.
Record the quotient 4 as the next digit in the result. 
Result so far: 140110.234
Deduct 2572 from 3110 and we're left with 538.
Since there are no more digits in the dividend, we add a zero to the remainder making it 5380, and continue the process.

On to step 12:
643 can be fit into 5380 8 times, resulting in a remainder of 236.
Use 8 as the next digit of our solution. 
Result so far: 140110.2348
Subtracting 5144 from 5380 leaves us with 236.
Since there are no more digits in the dividend, we add a zero to the remainder making it 2360, and continue the process.

On to step 13:
2360 divided by 643 is 3 with a remainder of 431.
Use 3 as the next digit of our solution. 
Result so far: 140110.23483
Subtract 1929 from 2360 to get 431.
Since there are no more digits in the dividend, we add a zero to the remainder making it 4310, and continue the process.

Step 14:
643 can be fit into 4310 6 times, resulting in a remainder of 452.
Record the quotient 6 as the next digit in the result. 
Result so far: 140110.234836
If we subtract 3858 from 4310, we get 452.
Since there are no more digits in the dividend, we add a zero to the remainder making it 4520, and continue the process.

Going ahead to step 15:
643 can be fit into 4520 7 times, resulting in a remainder of 19.
Put 7 as the next digit of the answer. 
Result so far: 140110.2348367
Subtracting 4501 from 4520 leaves us 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.

Advancing to step 16:
190 divided by 643 is 0 with a remainder of 190.
Put 0 as the next digit of the answer. 
Result so far: 140110.2348367
If we take 0 away from 190, we end up with 190.
Since there are no more digits in the dividend, we add a zero to the remainder making it 1900, and continue the process.

Our division results in 140110.2348367 with a remaining 1.9e-07.