We divide 238712 by 21
The aim is to understand the frequency of 21 in 238712.

Step 1:
The number 21 fits into 2 0 times, leaving a remainder of 2.
The next digit of our result is 0. 
Result so far: 0.0
If we take 0 away from 2, we end up with 2.
Include the next digit (3) from the dividend after 2, then repeat: 23 / 21

Let's proceed to step 2:
23 divided by 21 is 1 with a remainder of 2.
Put 1 as the next digit of the answer. 
Result so far: 1.0
If we take 21 away from 23, we end up with 2.
Take the next digit (8) from the dividend and append it to 2, then repeat: 28 / 21

Let's proceed to step 3:
28 divided by 21 is 1 with a remainder of 7.
Write down 1 as next digit of the result. 
Result so far: 11.0
Deduct 21 from 28 and we're left with 7.
Grab the next digit (7) from the dividend, add it to 7, then carry on: 77 / 21

Let's proceed to step 4:
77 divided by 21 is 3 with a remainder of 14.
Record the quotient 3 as the next digit in the result. 
Result so far: 113.0
The remainder is 14 after subtracting 63 from 77.
Take the next digit (1) from the dividend and append it to 14, then repeat: 141 / 21

Moving on to step 5:
141 divided by 21 is 6 with a remainder of 15.
Use 6 as the next digit of our solution. 
Result so far: 1136.0
Subtract 126 from 141 to get 15.
Fetch the next digit (2) from the dividend, attach it to 15 and continue: 152 / 21

On to step 6:
When dividing 152 by 21, we get 7 with a remainder of 5.
Record the quotient 7 as the next digit in the result. 
Result so far: 11367.0
If we take 147 away from 152, 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.

Moving on to step 7:
21 can be fit into 50 2 times, resulting in a remainder of 8.
The number 2 becomes the next digit in our result. 
Result so far: 11367.2
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.

On to step 8:
If we divide 80 by 21, we get 3 and a remainder of 17.
Put 3 as the next digit of the answer. 
Result so far: 11367.23
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 9:
21 can be fit into 170 8 times, resulting in a remainder of 2.
Write down 8 as next digit of the result. 
Result so far: 11367.238
The remainder is 2 after subtracting 168 from 170.
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 10:
21 goes into 20 0 times with a remainder of 20.
Write down 0 as next digit of the result. 
Result so far: 11367.238
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.

Let's proceed to step 11:
The number 21 fits into 200 9 times, leaving a remainder of 11.
Use 9 as the next digit of our solution. 
Result so far: 11367.23809
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 12:
21 can be fit into 110 5 times, resulting in a remainder of 5.
Record the quotient 5 as the next digit in the result. 
Result so far: 11367.238095
Subtracting 105 from 110 leaves us 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.

On to step 13:
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: 11367.2380952
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.

Going ahead to step 14:
21 can be fit into 80 3 times, resulting in a remainder of 17.
The next digit of our result is 3. 
Result so far: 11367.23809523
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.

The final result is 11367.23809523 with a remainder of 1.7e-08.