607234 divided by 21 
The aim is to understand the frequency of 21 in 607234.

Advancing to step 1:
The number 21 fits into 6 0 times, leaving a remainder of 6.
The next digit of our result is 0. 
Result so far: 0.0
The remainder is 6 after subtracting 0 from 6.
Take the next digit (0) from the dividend and append it to 6, then repeat: 60 / 21

On to step 2:
When dividing 60 by 21, we get 2 with a remainder of 18.
The number 2 becomes the next digit in our result. 
Result so far: 2.0
If we take 42 away from 60, we end up with 18.
Take the next digit (7) from the dividend and append it to 18, then repeat: 187 / 21

Moving on to step 3:
The number 21 fits into 187 8 times, leaving a remainder of 19.
Record the quotient 8 as the next digit in the result. 
Result so far: 28.0
Subtracting 168 from 187 leaves us with 19.
Fetch the next digit (2) from the dividend, attach it to 19 and continue: 192 / 21

Moving on to step 4:
192 divided by 21 is 9 with a remainder of 3.
Record the quotient 9 as the next digit in the result. 
Result so far: 289.0
If we subtract 189 from 192, we get 3.
Fetch the next digit (3) from the dividend, attach it to 3 and continue: 33 / 21

On to step 5:
21 can be fit into 33 1 times, resulting in a remainder of 12.
The number 1 becomes the next digit in our result. 
Result so far: 2891.0
If we subtract 21 from 33, we get 12.
Take the next digit (4) from the dividend and append it to 12, then repeat: 124 / 21

Step 6:
If we divide 124 by 21, we get 5 and a remainder of 19.
The next digit of our result is 5. 
Result so far: 28915.0
If we subtract 105 from 124, we 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.

Advancing to step 7:
21 can be fit into 190 9 times, resulting in a remainder of 1.
Use 9 as the next digit of our solution. 
Result so far: 28915.9
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:
If we divide 10 by 21, we get 0 and a remainder of 10.
The number 0 becomes the next digit in our result. 
Result so far: 28915.9
Subtracting 0 from 10 leaves us with 10.
Since there are no more digits in the dividend, we add a zero to the remainder making it 100, and continue the process.

Going ahead to step 9:
21 can be fit into 100 4 times, resulting in a remainder of 16.
Use 4 as the next digit of our solution. 
Result so far: 28915.904
If we subtract 84 from 100, we 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 10:
160 divided by 21 is 7 with a remainder of 13.
Put 7 as the next digit of the answer. 
Result so far: 28915.9047
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.

Advancing to step 11:
If we divide 130 by 21, we get 6 and a remainder of 4.
Write down 6 as next digit of the result. 
Result so far: 28915.90476
Subtracting 126 from 130 leaves us 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:
21 can be fit into 40 1 times, resulting in a remainder of 19.
Put 1 as the next digit of the answer. 
Result so far: 28915.904761
Subtracting 21 from 40 leaves us 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:
If we divide 190 by 21, we get 9 and a remainder of 1.
The number 9 becomes the next digit in our result. 
Result so far: 28915.9047619
Subtract 189 from 190 to get 1.
Since there are no more digits in the dividend, we add a zero to the remainder making it 10, and continue the process.

Let's proceed to step 14:
When dividing 10 by 21, we get 0 with a remainder of 10.
Put 0 as the next digit of the answer. 
Result so far: 28915.9047619
If we take 0 away from 10, we end up with 10.
Since there are no more digits in the dividend, we add a zero to the remainder making it 100, and continue the process.

The final outcome is 28915.9047619, with a leftover of 1e-08.