We look at the division of 766469 by 21 
The aim is to understand the frequency of 21 in 766469.

Moving on to step 1:
21 goes into 7 0 times with a remainder of 7.
Use 0 as the next digit of our solution. 
Result so far: 0.0
If we subtract 0 from 7, we get 7.
Append the next digit (6) from the dividend to 7 and continue with: 76 / 21

Advancing to step 2:
21 goes into 76 3 times with a remainder of 13.
Record the quotient 3 as the next digit in the result. 
Result so far: 3.0
If we take 63 away from 76, we end up with 13.
Include the next digit (6) from the dividend after 13, then repeat: 136 / 21

Advancing to step 3:
21 can be fit into 136 6 times, resulting in a remainder of 10.
Put 6 as the next digit of the answer. 
Result so far: 36.0
If we subtract 126 from 136, we get 10.
Include the next digit (4) from the dividend after 10, then repeat: 104 / 21

On to step 4:
When dividing 104 by 21, we get 4 with a remainder of 20.
Write down 4 as next digit of the result. 
Result so far: 364.0
Subtract 84 from 104 to get 20.
Take the next digit (6) from the dividend and append it to 20, then repeat: 206 / 21

Advancing to step 5:
21 goes into 206 9 times with a remainder of 17.
Use 9 as the next digit of our solution. 
Result so far: 3649.0
Deduct 189 from 206 and we're left with 17.
Grab the next digit (9) from the dividend, add it to 17, then carry on: 179 / 21

On to step 6:
The number 21 fits into 179 8 times, leaving a remainder of 11.
Use 8 as the next digit of our solution. 
Result so far: 36498.0
If we subtract 168 from 179, we get 11.
Since there are no more digits in the dividend, we add a zero to the remainder making it 110, and continue the process.

Step 7:
The number 21 fits into 110 5 times, leaving a remainder of 5.
Use 5 as the next digit of our solution. 
Result so far: 36498.5
Deduct 105 from 110 and we're left with 5.
Since there are no more digits in the dividend, we add a zero to the remainder making it 50, and continue the process.

Going ahead to step 8:
21 can be fit into 50 2 times, resulting in a remainder of 8.
Write down 2 as next digit of the result. 
Result so far: 36498.52
Deduct 42 from 50 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.

Let's proceed to step 9:
When dividing 80 by 21, we get 3 with a remainder of 17.
Write down 3 as next digit of the result. 
Result so far: 36498.523
Subtracting 63 from 80 leaves us with 17.
Since there are no more digits in the dividend, we add a zero to the remainder making it 170, and continue the process.

Let's proceed to step 10:
If we divide 170 by 21, we get 8 and a remainder of 2.
Put 8 as the next digit of the answer. 
Result so far: 36498.5238
Subtract 168 from 170 to get 2.
Since there are no more digits in the dividend, we add a zero to the remainder making it 20, and continue the process.

Going ahead to step 11:
When dividing 20 by 21, we get 0 with a remainder of 20.
Write down 0 as next digit of the result. 
Result so far: 36498.5238
If we take 0 away from 20, 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.

Step 12:
21 can be fit into 200 9 times, resulting in a remainder of 11.
The next digit of our result is 9. 
Result so far: 36498.523809
The remainder is 11 after subtracting 189 from 200.
Since there are no more digits in the dividend, we add a zero to the remainder making it 110, and continue the process.

Step 13:
21 goes into 110 5 times with a remainder of 5.
The next digit of our result is 5. 
Result so far: 36498.5238095
Subtract 105 from 110 to get 5.
Since there are no more digits in the dividend, we add a zero to the remainder making it 50, and continue the process.

Advancing to step 14:
The number 21 fits into 50 2 times, leaving a remainder of 8.
Use 2 as the next digit of our solution. 
Result so far: 36498.52380952
Subtracting 42 from 50 leaves us 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.

After the division, we end up with 36498.52380952 and a remainder of 8e-09.