We're dividing 190886 by 21 
The aim is to understand the frequency of 21 in 190886.

Step 1:
If we divide 1 by 21, we get 0 and a remainder of 1.
Record the quotient 0 as the next digit in the result. 
Result so far: 0.0
Subtracting 0 from 1 leaves us with 1.
Take the next digit (9) from the dividend and append it to 1, then repeat: 19 / 21

Let's proceed to step 2:
21 goes into 19 0 times with a remainder of 19.
Record the quotient 0 as the next digit in the result. 
Result so far: 0.0
Deduct 0 from 19 and we're left with 19.
Bring next digit (0) of the dividend behind the 19 and repeat the process: 190 / 21

Going ahead to step 3:
When dividing 190 by 21, we get 9 with a remainder of 1.
Write down 9 as next digit of the result. 
Result so far: 9.0
Deduct 189 from 190 and we're left with 1.
Include the next digit (8) from the dividend after 1, then repeat: 18 / 21

Advancing to step 4:
21 goes into 18 0 times with a remainder of 18.
Put 0 as the next digit of the answer. 
Result so far: 90.0
The remainder is 18 after subtracting 0 from 18.
Grab the next digit (8) from the dividend, add it to 18, then carry on: 188 / 21

Advancing to step 5:
21 can be fit into 188 8 times, resulting in a remainder of 20.
Write down 8 as next digit of the result. 
Result so far: 908.0
If we subtract 168 from 188, we get 20.
Fetch the next digit (6) from the dividend, attach it to 20 and continue: 206 / 21

Moving on to step 6:
21 can be fit into 206 9 times, resulting in a remainder of 17.
Put 9 as the next digit of the answer. 
Result so far: 9089.0
Subtract 189 from 206 to get 17.
Since there are no more digits in the dividend, we add a zero to the remainder making it 170, and continue the process.

Moving on to step 7:
The number 21 fits into 170 8 times, leaving a remainder of 2.
The next digit of our result is 8. 
Result so far: 9089.8
Deduct 168 from 170 and we're left with 2.
Since there are no more digits in the dividend, we add a zero to the remainder making it 20, and continue the process.

Step 8:
21 goes into 20 0 times with a remainder of 20.
The number 0 becomes the next digit in our result. 
Result so far: 9089.8
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 9:
200 divided by 21 is 9 with a remainder of 11.
Use 9 as the next digit of our solution. 
Result so far: 9089.809
Deduct 189 from 200 and we're left with 11.
Since there are no more digits in the dividend, we add a zero to the remainder making it 110, and continue the process.

Going ahead to step 10:
21 can be fit into 110 5 times, resulting in a remainder of 5.
Put 5 as the next digit of the answer. 
Result so far: 9089.8095
The remainder is 5 after subtracting 105 from 110.
Since there are no more digits in the dividend, we add a zero to the remainder making it 50, and continue the process.

Step 11:
21 goes into 50 2 times with a remainder of 8.
Write down 2 as next digit of the result. 
Result so far: 9089.80952
If we subtract 42 from 50, we get 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 12:
When dividing 80 by 21, we get 3 with a remainder of 17.
Use 3 as the next digit of our solution. 
Result so far: 9089.809523
If we take 63 away from 80, we end up 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.

Moving on to step 13:
If we divide 170 by 21, we get 8 and a remainder of 2.
The number 8 becomes the next digit in our result. 
Result so far: 9089.8095238
Deduct 168 from 170 and we're left with 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 14:
The number 21 fits into 20 0 times, leaving a remainder of 20.
The number 0 becomes the next digit in our result. 
Result so far: 9089.8095238
Subtract 0 from 20 to get 20.
Since there are no more digits in the dividend, we add a zero to the remainder making it 200, and continue the process.

The final outcome is 9089.8095238, with a leftover of 2e-08.