We divide 403232 by 21
The aim is to understand the frequency of 21 in 403232.

On to step 1:
If we divide 4 by 21, we get 0 and a remainder of 4.
Use 0 as the next digit of our solution. 
Result so far: 0.0
Subtracting 0 from 4 leaves us with 4.
Take the next digit (0) from the dividend and append it to 4, then repeat: 40 / 21

Advancing to step 2:
21 can be fit into 40 1 times, resulting in a remainder of 19.
Use 1 as the next digit of our solution. 
Result so far: 1.0
Deduct 21 from 40 and we're left with 19.
Append the next digit (3) from the dividend to 19 and continue with: 193 / 21

Step 3:
193 divided by 21 is 9 with a remainder of 4.
Record the quotient 9 as the next digit in the result. 
Result so far: 19.0
If we subtract 189 from 193, we get 4.
Fetch the next digit (2) from the dividend, attach it to 4 and continue: 42 / 21

Moving on to step 4:
When dividing 42 by 21, we get 2 with a remainder of 0.
Record the quotient 2 as the next digit in the result. 
Result so far: 192.0
Subtracting 42 from 42 leaves us with 0.
Fetch the next digit (3) from the dividend, attach it to 0 and continue: 3 / 21

Moving on to step 5:
21 goes into 3 0 times with a remainder of 3.
The number 0 becomes the next digit in our result. 
Result so far: 1920.0
If we subtract 0 from 3, we get 3.
Append the next digit (2) from the dividend to 3 and continue with: 32 / 21

Moving on to step 6:
32 divided by 21 is 1 with a remainder of 11.
Put 1 as the next digit of the answer. 
Result so far: 19201.0
If we subtract 21 from 32, we get 11.
Since there are no more digits in the dividend, we add a zero to the remainder making it 110, and continue the process.

Advancing to step 7:
21 can be fit into 110 5 times, resulting in a remainder of 5.
Write down 5 as next digit of the result. 
Result so far: 19201.5
If we subtract 105 from 110, we get 5.
Since there are no more digits in the dividend, we add a zero to the remainder making it 50, and continue the process.

Let's proceed to step 8:
When dividing 50 by 21, we get 2 with a remainder of 8.
Write down 2 as next digit of the result. 
Result so far: 19201.52
The remainder is 8 after subtracting 42 from 50.
Since there are no more digits in the dividend, we add a zero to the remainder making it 80, and continue the process.

Advancing to step 9:
21 goes into 80 3 times with a remainder of 17.
Record the quotient 3 as the next digit in the result. 
Result so far: 19201.523
Subtracting 63 from 80 leaves us 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.

Advancing to step 10:
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: 19201.5238
If we take 168 away from 170, we end up 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.

Advancing to step 11:
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: 19201.5238
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 12:
The number 21 fits into 200 9 times, leaving a remainder of 11.
Write down 9 as next digit of the result. 
Result so far: 19201.523809
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.

Moving on to step 13:
21 goes into 110 5 times with a remainder of 5.
The next digit of our result is 5. 
Result so far: 19201.5238095
Subtract 105 from 110 to get 5.
Since there are no more digits in the dividend, we add a zero to the remainder making it 50, and continue the process.

Moving on to step 14:
21 goes into 50 2 times with a remainder of 8.
Record the quotient 2 as the next digit in the result. 
Result so far: 19201.52380952
Deduct 42 from 50 and we're left with 8.
Since there are no more digits in the dividend, we add a zero to the remainder making it 80, and continue the process.

The final outcome is 19201.52380952, with a leftover of 8e-09.