399587 divided by 28 
The aim is to understand the frequency of 28 in 399587.

Advancing to step 1:
When dividing 3 by 28, we get 0 with a remainder of 3.
Write down 0 as next digit of the result. 
Result so far: 0.0
Deduct 0 from 3 and we're left with 3.
Append the next digit (9) from the dividend to 3 and continue with: 39 / 28

On to step 2:
The number 28 fits into 39 1 times, leaving a remainder of 11.
The next digit of our result is 1. 
Result so far: 1.0
Subtracting 28 from 39 leaves us with 11.
Take the next digit (9) from the dividend and append it to 11, then repeat: 119 / 28

Going ahead to step 3:
28 can be fit into 119 4 times, resulting in a remainder of 7.
Use 4 as the next digit of our solution. 
Result so far: 14.0
Deduct 112 from 119 and we're left with 7.
Bring next digit (5) of the dividend behind the 7 and repeat the process: 75 / 28

Moving on to step 4:
28 can be fit into 75 2 times, resulting in a remainder of 19.
The next digit of our result is 2. 
Result so far: 142.0
Subtracting 56 from 75 leaves us with 19.
Append the next digit (8) from the dividend to 19 and continue with: 198 / 28

Step 5:
The number 28 fits into 198 7 times, leaving a remainder of 2.
Record the quotient 7 as the next digit in the result. 
Result so far: 1427.0
Subtract 196 from 198 to get 2.
Bring next digit (7) of the dividend behind the 2 and repeat the process: 27 / 28

Advancing to step 6:
28 goes into 27 0 times with a remainder of 27.
Record the quotient 0 as the next digit in the result. 
Result so far: 14270.0
The remainder is 27 after subtracting 0 from 27.
Since there are no more digits in the dividend, we add a zero to the remainder making it 270, and continue the process.

Advancing to step 7:
270 divided by 28 is 9 with a remainder of 18.
Use 9 as the next digit of our solution. 
Result so far: 14270.9
If we subtract 252 from 270, we get 18.
Since there are no more digits in the dividend, we add a zero to the remainder making it 180, and continue the process.

Let's proceed to step 8:
28 goes into 180 6 times with a remainder of 12.
Put 6 as the next digit of the answer. 
Result so far: 14270.96
Subtract 168 from 180 to 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.

On to step 9:
120 divided by 28 is 4 with a remainder of 8.
Put 4 as the next digit of the answer. 
Result so far: 14270.964
The remainder is 8 after subtracting 112 from 120.
Since there are no more digits in the dividend, we add a zero to the remainder making it 80, and continue the process.

Step 10:
80 divided by 28 is 2 with a remainder of 24.
Put 2 as the next digit of the answer. 
Result so far: 14270.9642
Subtract 56 from 80 to get 24.
Since there are no more digits in the dividend, we add a zero to the remainder making it 240, and continue the process.

Moving on to step 11:
If we divide 240 by 28, we get 8 and a remainder of 16.
Record the quotient 8 as the next digit in the result. 
Result so far: 14270.96428
The remainder is 16 after subtracting 224 from 240.
Since there are no more digits in the dividend, we add a zero to the remainder making it 160, and continue the process.

Let's proceed to step 12:
28 goes into 160 5 times with a remainder of 20.
Put 5 as the next digit of the answer. 
Result so far: 14270.964285
If we take 140 away from 160, we end up with 20.
Since there are no more digits in the dividend, we add a zero to the remainder making it 200, and continue the process.

Moving on to step 13:
If we divide 200 by 28, we get 7 and a remainder of 4.
Use 7 as the next digit of our solution. 
Result so far: 14270.9642857
If we subtract 196 from 200, we get 4.
Since there are no more digits in the dividend, we add a zero to the remainder making it 40, and continue the process.

Step 14:
When dividing 40 by 28, we get 1 with a remainder of 12.
The number 1 becomes the next digit in our result. 
Result so far: 14270.96428571
If we take 28 away from 40, we end up with 12.
Since there are no more digits in the dividend, we add a zero to the remainder making it 120, and continue the process.

The final result is 14270.96428571 with a remainder of 1.2e-08.