Let's divide 153212 by 21
The aim is to understand the frequency of 21 in 153212.

Going ahead to step 1:
21 can be fit into 1 0 times, resulting in a remainder of 1.
Record the quotient 0 as the next digit in the result. 
Result so far: 0.0
Deduct 0 from 1 and we're left with 1.
Fetch the next digit (5) from the dividend, attach it to 1 and continue: 15 / 21

Advancing to step 2:
21 goes into 15 0 times with a remainder of 15.
The next digit of our result is 0. 
Result so far: 0.0
If we subtract 0 from 15, we get 15.
Append the next digit (3) from the dividend to 15 and continue with: 153 / 21

Step 3:
21 can be fit into 153 7 times, resulting in a remainder of 6.
The next digit of our result is 7. 
Result so far: 7.0
The remainder is 6 after subtracting 147 from 153.
Fetch the next digit (2) from the dividend, attach it to 6 and continue: 62 / 21

Let's proceed to step 4:
21 goes into 62 2 times with a remainder of 20.
The number 2 becomes the next digit in our result. 
Result so far: 72.0
Subtracting 42 from 62 leaves us with 20.
Grab the next digit (1) from the dividend, add it to 20, then carry on: 201 / 21

Advancing to step 5:
21 can be fit into 201 9 times, resulting in a remainder of 12.
The next digit of our result is 9. 
Result so far: 729.0
If we subtract 189 from 201, we get 12.
Fetch the next digit (2) from the dividend, attach it to 12 and continue: 122 / 21

On to step 6:
21 goes into 122 5 times with a remainder of 17.
Put 5 as the next digit of the answer. 
Result so far: 7295.0
Deduct 105 from 122 and we're left 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.

Going ahead to step 7:
The number 21 fits into 170 8 times, leaving a remainder of 2.
Write down 8 as next digit of the result. 
Result so far: 7295.8
Subtract 168 from 170 to 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.

Going ahead to step 8:
20 divided by 21 is 0 with a remainder of 20.
Put 0 as the next digit of the answer. 
Result so far: 7295.8
If we subtract 0 from 20, we 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.

Let's proceed to step 9:
21 goes into 200 9 times with a remainder of 11.
The number 9 becomes the next digit in our result. 
Result so far: 7295.809
Subtract 189 from 200 to 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.

Going ahead to step 10:
110 divided by 21 is 5 with a remainder of 5.
The number 5 becomes the next digit in our result. 
Result so far: 7295.8095
If we take 105 away from 110, we end up with 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 11:
21 can be fit into 50 2 times, resulting in a remainder of 8.
The next digit of our result is 2. 
Result so far: 7295.80952
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.

Advancing to step 12:
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: 7295.809523
The remainder is 17 after subtracting 63 from 80.
Since there are no more digits in the dividend, we add a zero to the remainder making it 170, and continue the process.

Step 13:
When dividing 170 by 21, we get 8 with a remainder of 2.
The number 8 becomes the next digit in our result. 
Result so far: 7295.8095238
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.

Moving on to step 14:
If we divide 20 by 21, we get 0 and a remainder of 20.
Use 0 as the next digit of our solution. 
Result so far: 7295.8095238
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.

In conclusion, the division gives 7295.8095238 with a balance of 2e-08.