616023 divided by 21 
The aim is to understand the frequency of 21 in 616023.

Let's proceed to step 1:
If we divide 6 by 21, we get 0 and a remainder of 6.
Write down 0 as next digit of the result. 
Result so far: 0.0
Subtract 0 from 6 to get 6.
Fetch the next digit (1) from the dividend, attach it to 6 and continue: 61 / 21

Step 2:
61 divided by 21 is 2 with a remainder of 19.
Use 2 as the next digit of our solution. 
Result so far: 2.0
Subtracting 42 from 61 leaves us with 19.
Fetch the next digit (6) from the dividend, attach it to 19 and continue: 196 / 21

Step 3:
If we divide 196 by 21, we get 9 and a remainder of 7.
Write down 9 as next digit of the result. 
Result so far: 29.0
If we subtract 189 from 196, we get 7.
Append the next digit (0) from the dividend to 7 and continue with: 70 / 21

Going ahead to step 4:
21 can be fit into 70 3 times, resulting in a remainder of 7.
Put 3 as the next digit of the answer. 
Result so far: 293.0
If we subtract 63 from 70, we get 7.
Append the next digit (2) from the dividend to 7 and continue with: 72 / 21

Going ahead to step 5:
21 can be fit into 72 3 times, resulting in a remainder of 9.
Write down 3 as next digit of the result. 
Result so far: 2933.0
Deduct 63 from 72 and we're left with 9.
Bring next digit (3) of the dividend behind the 9 and repeat the process: 93 / 21

Advancing to step 6:
If we divide 93 by 21, we get 4 and a remainder of 9.
The number 4 becomes the next digit in our result. 
Result so far: 29334.0
Subtract 84 from 93 to get 9.
Since there are no more digits in the dividend, we add a zero to the remainder making it 90, and continue the process.

Advancing to step 7:
21 can be fit into 90 4 times, resulting in a remainder of 6.
The number 4 becomes the next digit in our result. 
Result so far: 29334.4
The remainder is 6 after subtracting 84 from 90.
Since there are no more digits in the dividend, we add a zero to the remainder making it 60, and continue the process.

Step 8:
The number 21 fits into 60 2 times, leaving a remainder of 18.
Use 2 as the next digit of our solution. 
Result so far: 29334.42
Deduct 42 from 60 and we're left with 18.
Since there are no more digits in the dividend, we add a zero to the remainder making it 180, and continue the process.

On to step 9:
180 divided by 21 is 8 with a remainder of 12.
Record the quotient 8 as the next digit in the result. 
Result so far: 29334.428
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.

Advancing to step 10:
When dividing 120 by 21, we get 5 with a remainder of 15.
Record the quotient 5 as the next digit in the result. 
Result so far: 29334.4285
Subtract 105 from 120 to get 15.
Since there are no more digits in the dividend, we add a zero to the remainder making it 150, and continue the process.

Let's proceed to step 11:
21 can be fit into 150 7 times, resulting in a remainder of 3.
Write down 7 as next digit of the result. 
Result so far: 29334.42857
If we take 147 away from 150, we end up with 3.
Since there are no more digits in the dividend, we add a zero to the remainder making it 30, and continue the process.

Step 12:
If we divide 30 by 21, we get 1 and a remainder of 9.
Record the quotient 1 as the next digit in the result. 
Result so far: 29334.428571
Subtract 21 from 30 to get 9.
Since there are no more digits in the dividend, we add a zero to the remainder making it 90, and continue the process.

Step 13:
21 goes into 90 4 times with a remainder of 6.
Put 4 as the next digit of the answer. 
Result so far: 29334.4285714
Deduct 84 from 90 and we're left 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 14:
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: 29334.42857142
If we take 42 away from 60, we end up with 18.
Since there are no more digits in the dividend, we add a zero to the remainder making it 180, and continue the process.

In conclusion, the division gives 29334.42857142 with a balance of 1.8e-08.