Let's divide 521716 by 28
The aim is to understand the frequency of 28 in 521716.

Let's proceed to step 1:
If we divide 5 by 28, we get 0 and a remainder of 5.
The number 0 becomes the next digit in our result. 
Result so far: 0.0
If we subtract 0 from 5, we get 5.
Append the next digit (2) from the dividend to 5 and continue with: 52 / 28

Going ahead to step 2:
If we divide 52 by 28, we get 1 and a remainder of 24.
Record the quotient 1 as the next digit in the result. 
Result so far: 1.0
Subtract 28 from 52 to get 24.
Append the next digit (1) from the dividend to 24 and continue with: 241 / 28

Advancing to step 3:
28 goes into 241 8 times with a remainder of 17.
The number 8 becomes the next digit in our result. 
Result so far: 18.0
Subtracting 224 from 241 leaves us with 17.
Append the next digit (7) from the dividend to 17 and continue with: 177 / 28

Advancing to step 4:
If we divide 177 by 28, we get 6 and a remainder of 9.
Record the quotient 6 as the next digit in the result. 
Result so far: 186.0
Subtracting 168 from 177 leaves us with 9.
Append the next digit (1) from the dividend to 9 and continue with: 91 / 28

Moving on to step 5:
When dividing 91 by 28, we get 3 with a remainder of 7.
The number 3 becomes the next digit in our result. 
Result so far: 1863.0
Deduct 84 from 91 and we're left with 7.
Include the next digit (6) from the dividend after 7, then repeat: 76 / 28

Step 6:
If we divide 76 by 28, we get 2 and a remainder of 20.
Record the quotient 2 as the next digit in the result. 
Result so far: 18632.0
Deduct 56 from 76 and we're left 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 7:
If we divide 200 by 28, we get 7 and a remainder of 4.
Record the quotient 7 as the next digit in the result. 
Result so far: 18632.7
Subtract 196 from 200 to 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.

Let's proceed to step 8:
When dividing 40 by 28, we get 1 with a remainder of 12.
Put 1 as the next digit of the answer. 
Result so far: 18632.71
If we subtract 28 from 40, 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.

Advancing to step 9:
28 can be fit into 120 4 times, resulting in a remainder of 8.
Put 4 as the next digit of the answer. 
Result so far: 18632.714
Deduct 112 from 120 and we're left with 8.
Since there are no more digits in the dividend, we add a zero to the remainder making it 80, and continue the process.

Moving on to step 10:
28 can be fit into 80 2 times, resulting in a remainder of 24.
Record the quotient 2 as the next digit in the result. 
Result so far: 18632.7142
If we take 56 away from 80, we end up with 24.
Since there are no more digits in the dividend, we add a zero to the remainder making it 240, and continue the process.

On to step 11:
When dividing 240 by 28, we get 8 with a remainder of 16.
Use 8 as the next digit of our solution. 
Result so far: 18632.71428
Subtract 224 from 240 to get 16.
Since there are no more digits in the dividend, we add a zero to the remainder making it 160, and continue the process.

On to step 12:
28 can be fit into 160 5 times, resulting in a remainder of 20.
The number 5 becomes the next digit in our result. 
Result so far: 18632.714285
If we subtract 140 from 160, we get 20.
Since there are no more digits in the dividend, we add a zero to the remainder making it 200, and continue the process.

Going ahead to step 13:
When dividing 200 by 28, we get 7 with a remainder of 4.
Write down 7 as next digit of the result. 
Result so far: 18632.7142857
Deduct 196 from 200 and we're left with 4.
Since there are no more digits in the dividend, we add a zero to the remainder making it 40, and continue the process.

On to step 14:
If we divide 40 by 28, we get 1 and a remainder of 12.
The next digit of our result is 1. 
Result so far: 18632.71428571
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.

After the division, we end up with 18632.71428571 and a remainder of 1.2e-08.