602685 ÷ 21 
The aim is to understand the frequency of 21 in 602685.

Let's proceed to step 1:
21 can be fit into 6 0 times, resulting in a remainder of 6.
Record the quotient 0 as the next digit in the result. 
Result so far: 0.0
The remainder is 6 after subtracting 0 from 6.
Grab the next digit (0) from the dividend, add it to 6, then carry on: 60 / 21

On to step 2:
21 can be fit into 60 2 times, resulting in a remainder of 18.
Write down 2 as next digit of the result. 
Result so far: 2.0
Subtract 42 from 60 to get 18.
Include the next digit (2) from the dividend after 18, then repeat: 182 / 21

Let's proceed to step 3:
When dividing 182 by 21, we get 8 with a remainder of 14.
The next digit of our result is 8. 
Result so far: 28.0
The remainder is 14 after subtracting 168 from 182.
Bring next digit (6) of the dividend behind the 14 and repeat the process: 146 / 21

Step 4:
The number 21 fits into 146 6 times, leaving a remainder of 20.
Put 6 as the next digit of the answer. 
Result so far: 286.0
Deduct 126 from 146 and we're left with 20.
Bring next digit (8) of the dividend behind the 20 and repeat the process: 208 / 21

Moving on to step 5:
The number 21 fits into 208 9 times, leaving a remainder of 19.
The next digit of our result is 9. 
Result so far: 2869.0
If we take 189 away from 208, we end up with 19.
Append the next digit (5) from the dividend to 19 and continue with: 195 / 21

Let's proceed to step 6:
21 goes into 195 9 times with a remainder of 6.
Use 9 as the next digit of our solution. 
Result so far: 28699.0
Subtracting 189 from 195 leaves us with 6.
Since there are no more digits in the dividend, we add a zero to the remainder making it 60, and continue the process.

Moving on to step 7:
60 divided by 21 is 2 with a remainder of 18.
The number 2 becomes the next digit in our result. 
Result so far: 28699.2
If we subtract 42 from 60, 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.

Moving on to step 8:
21 goes into 180 8 times with a remainder of 12.
Write down 8 as next digit of the result. 
Result so far: 28699.28
If we take 168 away from 180, 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.

Advancing to step 9:
21 can be fit into 120 5 times, resulting in a remainder of 15.
Write down 5 as next digit of the result. 
Result so far: 28699.285
If we take 105 away from 120, we end up with 15.
Since there are no more digits in the dividend, we add a zero to the remainder making it 150, and continue the process.

Moving on to step 10:
If we divide 150 by 21, we get 7 and a remainder of 3.
Write down 7 as next digit of the result. 
Result so far: 28699.2857
Subtract 147 from 150 to get 3.
Since there are no more digits in the dividend, we add a zero to the remainder making it 30, and continue the process.

Going ahead to step 11:
21 goes into 30 1 times with a remainder of 9.
Write down 1 as next digit of the result. 
Result so far: 28699.28571
Subtracting 21 from 30 leaves us with 9.
Since there are no more digits in the dividend, we add a zero to the remainder making it 90, and continue the process.

Going ahead to step 12:
If we divide 90 by 21, we get 4 and a remainder of 6.
Record the quotient 4 as the next digit in the result. 
Result so far: 28699.285714
Subtracting 84 from 90 leaves us with 6.
Since there are no more digits in the dividend, we add a zero to the remainder making it 60, and continue the process.

Let's proceed to step 13:
60 divided by 21 is 2 with a remainder of 18.
Put 2 as the next digit of the answer. 
Result so far: 28699.2857142
If we subtract 42 from 60, 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.

Going ahead to step 14:
If we divide 180 by 21, we get 8 and a remainder of 12.
Record the quotient 8 as the next digit in the result. 
Result so far: 28699.28571428
The remainder is 12 after subtracting 168 from 180.
Since there are no more digits in the dividend, we add a zero to the remainder making it 120, and continue the process.

In conclusion, the division gives 28699.28571428 with a balance of 1.2e-08.