212024 ÷ 21 
The aim is to understand the frequency of 21 in 212024.

Let's proceed to step 1:
If we divide 2 by 21, we get 0 and a remainder of 2.
Put 0 as the next digit of the answer. 
Result so far: 0.0
The remainder is 2 after subtracting 0 from 2.
Take the next digit (1) from the dividend and append it to 2, then repeat: 21 / 21

Advancing to step 2:
21 can be fit into 21 1 times, resulting in a remainder of 0.
Record the quotient 1 as the next digit in the result. 
Result so far: 1.0
Deduct 21 from 21 and we're left with 0.
Append the next digit (2) from the dividend to 0 and continue with: 2 / 21

Moving on to step 3:
21 goes into 2 0 times with a remainder of 2.
Record the quotient 0 as the next digit in the result. 
Result so far: 10.0
Subtracting 0 from 2 leaves us with 2.
Take the next digit (0) from the dividend and append it to 2, then repeat: 20 / 21

Moving on to step 4:
When dividing 20 by 21, we get 0 with a remainder of 20.
Record the quotient 0 as the next digit in the result. 
Result so far: 100.0
The remainder is 20 after subtracting 0 from 20.
Append the next digit (2) from the dividend to 20 and continue with: 202 / 21

On to step 5:
The number 21 fits into 202 9 times, leaving a remainder of 13.
The number 9 becomes the next digit in our result. 
Result so far: 1009.0
Subtracting 189 from 202 leaves us with 13.
Include the next digit (4) from the dividend after 13, then repeat: 134 / 21

Step 6:
If we divide 134 by 21, we get 6 and a remainder of 8.
The number 6 becomes the next digit in our result. 
Result so far: 10096.0
If we take 126 away from 134, we end up 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.

Step 7:
The number 21 fits into 80 3 times, leaving a remainder of 17.
Put 3 as the next digit of the answer. 
Result so far: 10096.3
Subtract 63 from 80 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.

Going ahead to step 8:
21 goes into 170 8 times with a remainder of 2.
Write down 8 as next digit of the result. 
Result so far: 10096.38
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.

Moving on to step 9:
20 divided by 21 is 0 with a remainder of 20.
Write down 0 as next digit of the result. 
Result so far: 10096.38
Subtracting 0 from 20 leaves us 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.

Going ahead to step 10:
If we divide 200 by 21, we get 9 and a remainder of 11.
The next digit of our result is 9. 
Result so far: 10096.3809
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.

On to step 11:
When dividing 110 by 21, we get 5 with a remainder of 5.
The next digit of our result is 5. 
Result so far: 10096.38095
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.

Advancing to step 12:
The number 21 fits into 50 2 times, leaving a remainder of 8.
Write down 2 as next digit of the result. 
Result so far: 10096.380952
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.

Going ahead to step 13:
If we divide 80 by 21, we get 3 and a remainder of 17.
Write down 3 as next digit of the result. 
Result so far: 10096.3809523
Subtract 63 from 80 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.

Advancing to step 14:
When dividing 170 by 21, we get 8 with a remainder of 2.
Record the quotient 8 as the next digit in the result. 
Result so far: 10096.38095238
If we subtract 168 from 170, we get 2.
Since there are no more digits in the dividend, we add a zero to the remainder making it 20, and continue the process.

After the division, we end up with 10096.38095238 and a remainder of 2e-09.