Let's divide 919918 by 21
The aim is to understand the frequency of 21 in 919918.

Step 1:
The number 21 fits into 9 0 times, leaving a remainder of 9.
The next digit of our result is 0. 
Result so far: 0.0
If we take 0 away from 9, we end up with 9.
Include the next digit (1) from the dividend after 9, then repeat: 91 / 21

Moving on to step 2:
The number 21 fits into 91 4 times, leaving a remainder of 7.
Record the quotient 4 as the next digit in the result. 
Result so far: 4.0
If we take 84 away from 91, we end up with 7.
Take the next digit (9) from the dividend and append it to 7, then repeat: 79 / 21

Step 3:
When dividing 79 by 21, we get 3 with a remainder of 16.
Write down 3 as next digit of the result. 
Result so far: 43.0
If we take 63 away from 79, we end up with 16.
Bring next digit (9) of the dividend behind the 16 and repeat the process: 169 / 21

Going ahead to step 4:
When dividing 169 by 21, we get 8 with a remainder of 1.
Put 8 as the next digit of the answer. 
Result so far: 438.0
If we take 168 away from 169, we end up with 1.
Fetch the next digit (1) from the dividend, attach it to 1 and continue: 11 / 21

Moving on to step 5:
21 can be fit into 11 0 times, resulting in a remainder of 11.
Write down 0 as next digit of the result. 
Result so far: 4380.0
If we subtract 0 from 11, we get 11.
Append the next digit (8) from the dividend to 11 and continue with: 118 / 21

Going ahead to step 6:
When dividing 118 by 21, we get 5 with a remainder of 13.
Write down 5 as next digit of the result. 
Result so far: 43805.0
If we take 105 away from 118, we end up 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.

Moving on to step 7:
If we divide 130 by 21, we get 6 and a remainder of 4.
The next digit of our result is 6. 
Result so far: 43805.6
If we subtract 126 from 130, we get 4.
Since there are no more digits in the dividend, we add a zero to the remainder making it 40, and continue the process.

Let's proceed to step 8:
40 divided by 21 is 1 with a remainder of 19.
The number 1 becomes the next digit in our result. 
Result so far: 43805.61
Subtract 21 from 40 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.

Going ahead to step 9:
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: 43805.619
Subtracting 189 from 190 leaves us 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.

Step 10:
When dividing 10 by 21, we get 0 with a remainder of 10.
The next digit of our result is 0. 
Result so far: 43805.619
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.

Advancing to step 11:
If we divide 100 by 21, we get 4 and a remainder of 16.
The next digit of our result is 4. 
Result so far: 43805.61904
Subtracting 84 from 100 leaves us 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.

Moving on to step 12:
When dividing 160 by 21, we get 7 with a remainder of 13.
Record the quotient 7 as the next digit in the result. 
Result so far: 43805.619047
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 13:
130 divided by 21 is 6 with a remainder of 4.
The next digit of our result is 6. 
Result so far: 43805.6190476
If we take 126 away from 130, we end up 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.

Advancing to step 14:
The number 21 fits into 40 1 times, leaving a remainder of 19.
Use 1 as the next digit of our solution. 
Result so far: 43805.61904761
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.

After the division, we end up with 43805.61904761 and a remainder of 1.9e-08.