473136 ÷ 21 
The aim is to understand the frequency of 21 in 473136.

On to step 1:
When dividing 4 by 21, we get 0 with a remainder of 4.
The number 0 becomes the next digit in our result. 
Result so far: 0.0
Deduct 0 from 4 and we're left with 4.
Fetch the next digit (7) from the dividend, attach it to 4 and continue: 47 / 21

Going ahead to step 2:
21 goes into 47 2 times with a remainder of 5.
Put 2 as the next digit of the answer. 
Result so far: 2.0
If we subtract 42 from 47, we get 5.
Fetch the next digit (3) from the dividend, attach it to 5 and continue: 53 / 21

Moving on to step 3:
21 goes into 53 2 times with a remainder of 11.
Put 2 as the next digit of the answer. 
Result so far: 22.0
The remainder is 11 after subtracting 42 from 53.
Bring next digit (1) of the dividend behind the 11 and repeat the process: 111 / 21

Advancing to step 4:
111 divided by 21 is 5 with a remainder of 6.
Record the quotient 5 as the next digit in the result. 
Result so far: 225.0
Subtract 105 from 111 to get 6.
Include the next digit (3) from the dividend after 6, then repeat: 63 / 21

Moving on to step 5:
21 can be fit into 63 3 times, resulting in a remainder of 0.
Write down 3 as next digit of the result. 
Result so far: 2253.0
If we take 63 away from 63, we end up with 0.
Grab the next digit (6) from the dividend, add it to 0, then carry on: 6 / 21

Going ahead to step 6:
6 divided by 21 is 0 with a remainder of 6.
Put 0 as the next digit of the answer. 
Result so far: 22530.0
If we subtract 0 from 6, we get 6.
Since there are no more digits in the dividend, we add a zero to the remainder making it 60, and continue the process.

On to step 7:
60 divided by 21 is 2 with a remainder of 18.
The number 2 becomes the next digit in our result. 
Result so far: 22530.2
Subtract 42 from 60 to get 18.
Since there are no more digits in the dividend, we add a zero to the remainder making it 180, and continue the process.

Let's proceed to step 8:
The number 21 fits into 180 8 times, leaving a remainder of 12.
Record the quotient 8 as the next digit in the result. 
Result so far: 22530.28
Subtracting 168 from 180 leaves us with 12.
Since there are no more digits in the dividend, we add a zero to the remainder making it 120, and continue the process.

Step 9:
120 divided by 21 is 5 with a remainder of 15.
The number 5 becomes the next digit in our result. 
Result so far: 22530.285
The remainder is 15 after subtracting 105 from 120.
Since there are no more digits in the dividend, we add a zero to the remainder making it 150, and continue the process.

Going ahead to step 10:
21 can be fit into 150 7 times, resulting in a remainder of 3.
The number 7 becomes the next digit in our result. 
Result so far: 22530.2857
Deduct 147 from 150 and we're left with 3.
Since there are no more digits in the dividend, we add a zero to the remainder making it 30, and continue the process.

Step 11:
When dividing 30 by 21, we get 1 with a remainder of 9.
Put 1 as the next digit of the answer. 
Result so far: 22530.28571
If we subtract 21 from 30, we get 9.
Since there are no more digits in the dividend, we add a zero to the remainder making it 90, and continue the process.

Step 12:
If we divide 90 by 21, we get 4 and a remainder of 6.
The next digit of our result is 4. 
Result so far: 22530.285714
Subtract 84 from 90 to get 6.
Since there are no more digits in the dividend, we add a zero to the remainder making it 60, and continue the process.

Going ahead to step 13:
If we divide 60 by 21, we get 2 and a remainder of 18.
Record the quotient 2 as the next digit in the result. 
Result so far: 22530.2857142
If we subtract 42 from 60, we get 18.
Since there are no more digits in the dividend, we add a zero to the remainder making it 180, and continue the process.

Let's proceed to step 14:
21 goes into 180 8 times with a remainder of 12.
Use 8 as the next digit of our solution. 
Result so far: 22530.28571428
Subtract 168 from 180 to get 12.
Since there are no more digits in the dividend, we add a zero to the remainder making it 120, and continue the process.

Our division results in 22530.28571428 with a remaining 1.2e-08.