We look at the division of 626047 by 21 
The aim is to understand the frequency of 21 in 626047.

On to step 1:
If we divide 6 by 21, we get 0 and a remainder of 6.
Put 0 as the next digit of the answer. 
Result so far: 0.0
Subtracting 0 from 6 leaves us with 6.
Bring next digit (2) of the dividend behind the 6 and repeat the process: 62 / 21

Advancing to step 2:
When dividing 62 by 21, we get 2 with a remainder of 20.
Use 2 as the next digit of our solution. 
Result so far: 2.0
Subtract 42 from 62 to get 20.
Take the next digit (6) from the dividend and append it to 20, then repeat: 206 / 21

Advancing to step 3:
When dividing 206 by 21, we get 9 with a remainder of 17.
Put 9 as the next digit of the answer. 
Result so far: 29.0
If we subtract 189 from 206, we get 17.
Append the next digit (0) from the dividend to 17 and continue with: 170 / 21

Let's proceed to step 4:
170 divided by 21 is 8 with a remainder of 2.
Record the quotient 8 as the next digit in the result. 
Result so far: 298.0
If we subtract 168 from 170, we get 2.
Bring next digit (4) of the dividend behind the 2 and repeat the process: 24 / 21

On to step 5:
21 goes into 24 1 times with a remainder of 3.
Use 1 as the next digit of our solution. 
Result so far: 2981.0
Subtract 21 from 24 to get 3.
Include the next digit (7) from the dividend after 3, then repeat: 37 / 21

Advancing to step 6:
37 divided by 21 is 1 with a remainder of 16.
Put 1 as the next digit of the answer. 
Result so far: 29811.0
If we subtract 21 from 37, we get 16.
Since there are no more digits in the dividend, we add a zero to the remainder making it 160, and continue the process.

Advancing to step 7:
The number 21 fits into 160 7 times, leaving a remainder of 13.
Put 7 as the next digit of the answer. 
Result so far: 29811.7
Subtracting 147 from 160 leaves us with 13.
Since there are no more digits in the dividend, we add a zero to the remainder making it 130, and continue the process.

Advancing to step 8:
21 goes into 130 6 times with a remainder of 4.
Record the quotient 6 as the next digit in the result. 
Result so far: 29811.76
The remainder is 4 after subtracting 126 from 130.
Since there are no more digits in the dividend, we add a zero to the remainder making it 40, and continue the process.

Advancing to step 9:
21 can be fit into 40 1 times, resulting in a remainder of 19.
Put 1 as the next digit of the answer. 
Result so far: 29811.761
If we take 21 away from 40, we end up with 19.
Since there are no more digits in the dividend, we add a zero to the remainder making it 190, and continue the process.

Advancing to step 10:
If we divide 190 by 21, we get 9 and a remainder of 1.
The number 9 becomes the next digit in our result. 
Result so far: 29811.7619
If we take 189 away from 190, we end up with 1.
Since there are no more digits in the dividend, we add a zero to the remainder making it 10, and continue the process.

Step 11:
If we divide 10 by 21, we get 0 and a remainder of 10.
Write down 0 as next digit of the result. 
Result so far: 29811.7619
If we subtract 0 from 10, we get 10.
Since there are no more digits in the dividend, we add a zero to the remainder making it 100, and continue the process.

On to step 12:
21 goes into 100 4 times with a remainder of 16.
Write down 4 as next digit of the result. 
Result so far: 29811.761904
If we take 84 away from 100, we end up with 16.
Since there are no more digits in the dividend, we add a zero to the remainder making it 160, and continue the process.

Advancing to step 13:
160 divided by 21 is 7 with a remainder of 13.
The number 7 becomes the next digit in our result. 
Result so far: 29811.7619047
If we subtract 147 from 160, we get 13.
Since there are no more digits in the dividend, we add a zero to the remainder making it 130, and continue the process.

Going ahead to step 14:
21 goes into 130 6 times with a remainder of 4.
Use 6 as the next digit of our solution. 
Result so far: 29811.76190476
The remainder is 4 after subtracting 126 from 130.
Since there are no more digits in the dividend, we add a zero to the remainder making it 40, and continue the process.

In conclusion, the division gives 29811.76190476 with a balance of 4e-09.