756565 divided by 21 
The aim is to understand the frequency of 21 in 756565.

Let's proceed to step 1:
21 can be fit into 7 0 times, resulting in a remainder of 7.
The number 0 becomes the next digit in our result. 
Result so far: 0.0
The remainder is 7 after subtracting 0 from 7.
Fetch the next digit (5) from the dividend, attach it to 7 and continue: 75 / 21

Let's proceed to step 2:
When dividing 75 by 21, we get 3 with a remainder of 12.
Put 3 as the next digit of the answer. 
Result so far: 3.0
Subtracting 63 from 75 leaves us with 12.
Grab the next digit (6) from the dividend, add it to 12, then carry on: 126 / 21

Advancing to step 3:
126 divided by 21 is 6 with a remainder of 0.
Record the quotient 6 as the next digit in the result. 
Result so far: 36.0
Subtract 126 from 126 to get 0.
Grab the next digit (5) from the dividend, add it to 0, then carry on: 5 / 21

Going ahead to step 4:
5 divided by 21 is 0 with a remainder of 5.
Put 0 as the next digit of the answer. 
Result so far: 360.0
Subtract 0 from 5 to get 5.
Fetch the next digit (6) from the dividend, attach it to 5 and continue: 56 / 21

Step 5:
21 goes into 56 2 times with a remainder of 14.
The next digit of our result is 2. 
Result so far: 3602.0
If we subtract 42 from 56, we get 14.
Grab the next digit (5) from the dividend, add it to 14, then carry on: 145 / 21

Let's proceed to step 6:
When dividing 145 by 21, we get 6 with a remainder of 19.
Write down 6 as next digit of the result. 
Result so far: 36026.0
Subtract 126 from 145 to get 19.
Since there are no more digits in the dividend, we add a zero to the remainder making it 190, and continue the process.

Moving on to step 7:
The number 21 fits into 190 9 times, leaving a remainder of 1.
Record the quotient 9 as the next digit in the result. 
Result so far: 36026.9
Deduct 189 from 190 and we're left with 1.
Since there are no more digits in the dividend, we add a zero to the remainder making it 10, and continue the process.

Moving on to step 8:
21 can be fit into 10 0 times, resulting in a remainder of 10.
The next digit of our result is 0. 
Result so far: 36026.9
The remainder is 10 after subtracting 0 from 10.
Since there are no more digits in the dividend, we add a zero to the remainder making it 100, and continue the process.

On to step 9:
The number 21 fits into 100 4 times, leaving a remainder of 16.
Use 4 as the next digit of our solution. 
Result so far: 36026.904
Deduct 84 from 100 and we're left with 16.
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 10:
When dividing 160 by 21, we get 7 with a remainder of 13.
Use 7 as the next digit of our solution. 
Result so far: 36026.9047
Deduct 147 from 160 and we're left with 13.
Since there are no more digits in the dividend, we add a zero to the remainder making it 130, and continue the process.

On to step 11:
130 divided by 21 is 6 with a remainder of 4.
The next digit of our result is 6. 
Result so far: 36026.90476
Deduct 126 from 130 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 12:
The number 21 fits into 40 1 times, leaving a remainder of 19.
Write down 1 as next digit of the result. 
Result so far: 36026.904761
Deduct 21 from 40 and we're left 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.

Moving on to step 13:
21 can be fit into 190 9 times, resulting in a remainder of 1.
Record the quotient 9 as the next digit in the result. 
Result so far: 36026.9047619
The remainder is 1 after subtracting 189 from 190.
Since there are no more digits in the dividend, we add a zero to the remainder making it 10, and continue the process.

Moving on to step 14:
21 goes into 10 0 times with a remainder of 10.
Put 0 as the next digit of the answer. 
Result so far: 36026.9047619
If we subtract 0 from 10, we get 10.
Since there are no more digits in the dividend, we add a zero to the remainder making it 100, and continue the process.

Our division results in 36026.9047619 with a remaining 1e-08.