We look at the division of 87990 by 43 
The aim is to understand the frequency of 43 in 87990.

On to step 1:
8 divided by 43 is 0 with a remainder of 8.
Record the quotient 0 as the next digit in the result. 
Result so far: 0.0
Subtracting 0 from 8 leaves us with 8.
Take the next digit (7) from the dividend and append it to 8, then repeat: 87 / 43

Advancing to step 2:
43 can be fit into 87 2 times, resulting in a remainder of 1.
Use 2 as the next digit of our solution. 
Result so far: 2.0
If we take 86 away from 87, we end up with 1.
Grab the next digit (9) from the dividend, add it to 1, then carry on: 19 / 43

Let's proceed to step 3:
43 can be fit into 19 0 times, resulting in a remainder of 19.
Use 0 as the next digit of our solution. 
Result so far: 20.0
Subtracting 0 from 19 leaves us with 19.
Bring next digit (9) of the dividend behind the 19 and repeat the process: 199 / 43

Let's proceed to step 4:
If we divide 199 by 43, we get 4 and a remainder of 27.
Record the quotient 4 as the next digit in the result. 
Result so far: 204.0
Deduct 172 from 199 and we're left with 27.
Include the next digit (0) from the dividend after 27, then repeat: 270 / 43

Going ahead to step 5:
270 divided by 43 is 6 with a remainder of 12.
The number 6 becomes the next digit in our result. 
Result so far: 2046.0
If we subtract 258 from 270, we get 12.
Since there are no more digits in the dividend, we add a zero to the remainder making it 120, and continue the process.

Going ahead to step 6:
43 can be fit into 120 2 times, resulting in a remainder of 34.
The next digit of our result is 2. 
Result so far: 2046.2
Subtracting 86 from 120 leaves us with 34.
Since there are no more digits in the dividend, we add a zero to the remainder making it 340, and continue the process.

Moving on to step 7:
43 goes into 340 7 times with a remainder of 39.
The next digit of our result is 7. 
Result so far: 2046.27
If we take 301 away from 340, we end up with 39.
Since there are no more digits in the dividend, we add a zero to the remainder making it 390, and continue the process.

Step 8:
The number 43 fits into 390 9 times, leaving a remainder of 3.
Put 9 as the next digit of the answer. 
Result so far: 2046.279
The remainder is 3 after subtracting 387 from 390.
Since there are no more digits in the dividend, we add a zero to the remainder making it 30, and continue the process.

Step 9:
43 can be fit into 30 0 times, resulting in a remainder of 30.
Use 0 as the next digit of our solution. 
Result so far: 2046.279
Subtract 0 from 30 to get 30.
Since there are no more digits in the dividend, we add a zero to the remainder making it 300, and continue the process.

Going ahead to step 10:
When dividing 300 by 43, we get 6 with a remainder of 42.
Use 6 as the next digit of our solution. 
Result so far: 2046.27906
Deduct 258 from 300 and we're left with 42.
Since there are no more digits in the dividend, we add a zero to the remainder making it 420, and continue the process.

Step 11:
43 can be fit into 420 9 times, resulting in a remainder of 33.
Put 9 as the next digit of the answer. 
Result so far: 2046.279069
Deduct 387 from 420 and we're left with 33.
Since there are no more digits in the dividend, we add a zero to the remainder making it 330, and continue the process.

Step 12:
If we divide 330 by 43, we get 7 and a remainder of 29.
Write down 7 as next digit of the result. 
Result so far: 2046.2790697
Subtracting 301 from 330 leaves us with 29.
Since there are no more digits in the dividend, we add a zero to the remainder making it 290, and continue the process.

Moving on to step 13:
The number 43 fits into 290 6 times, leaving a remainder of 32.
Record the quotient 6 as the next digit in the result. 
Result so far: 2046.27906976
Subtract 258 from 290 to get 32.
Since there are no more digits in the dividend, we add a zero to the remainder making it 320, and continue the process.

After the division, we end up with 2046.27906976 and a remainder of 3.2e-08.