We look at the division of 700549 by 21 
The aim is to understand the frequency of 21 in 700549.

Step 1:
21 goes into 7 0 times with a remainder of 7.
Write down 0 as next digit of the result. 
Result so far: 0.0
The remainder is 7 after subtracting 0 from 7.
Grab the next digit (0) from the dividend, add it to 7, then carry on: 70 / 21

Step 2:
70 divided by 21 is 3 with a remainder of 7.
The next digit of our result is 3. 
Result so far: 3.0
Subtracting 63 from 70 leaves us with 7.
Include the next digit (0) from the dividend after 7, then repeat: 70 / 21

Step 3:
70 divided by 21 is 3 with a remainder of 7.
Record the quotient 3 as the next digit in the result. 
Result so far: 33.0
Subtract 63 from 70 to get 7.
Fetch the next digit (5) from the dividend, attach it to 7 and continue: 75 / 21

Let's proceed to step 4:
21 can be fit into 75 3 times, resulting in a remainder of 12.
The next digit of our result is 3. 
Result so far: 333.0
If we subtract 63 from 75, we get 12.
Append the next digit (4) from the dividend to 12 and continue with: 124 / 21

Going ahead to step 5:
124 divided by 21 is 5 with a remainder of 19.
The number 5 becomes the next digit in our result. 
Result so far: 3335.0
Deduct 105 from 124 and we're left with 19.
Take the next digit (9) from the dividend and append it to 19, then repeat: 199 / 21

Going ahead to step 6:
199 divided by 21 is 9 with a remainder of 10.
Put 9 as the next digit of the answer. 
Result so far: 33359.0
If we subtract 189 from 199, 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.

Advancing to step 7:
21 can be fit into 100 4 times, resulting in a remainder of 16.
Write down 4 as next digit of the result. 
Result so far: 33359.4
The remainder is 16 after subtracting 84 from 100.
Since there are no more digits in the dividend, we add a zero to the remainder making it 160, and continue the process.

Moving on to step 8:
160 divided by 21 is 7 with a remainder of 13.
Record the quotient 7 as the next digit in the result. 
Result so far: 33359.47
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.

On to step 9:
130 divided by 21 is 6 with a remainder of 4.
Write down 6 as next digit of the result. 
Result so far: 33359.476
Deduct 126 from 130 and we're left with 4.
Since there are no more digits in the dividend, we add a zero to the remainder making it 40, and continue the process.

Moving on to step 10:
40 divided by 21 is 1 with a remainder of 19.
Write down 1 as next digit of the result. 
Result so far: 33359.4761
Subtracting 21 from 40 leaves us 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.

Moving on to step 11:
The number 21 fits into 190 9 times, leaving a remainder of 1.
The next digit of our result is 9. 
Result so far: 33359.47619
Deduct 189 from 190 and we're left 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.

Going ahead to step 12:
When dividing 10 by 21, we get 0 with a remainder of 10.
The number 0 becomes the next digit in our result. 
Result so far: 33359.47619
If we take 0 away from 10, we end up with 10.
Since there are no more digits in the dividend, we add a zero to the remainder making it 100, and continue the process.

Advancing to step 13:
21 goes into 100 4 times with a remainder of 16.
Write down 4 as next digit of the result. 
Result so far: 33359.4761904
Deduct 84 from 100 and we're left 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 14:
If we divide 160 by 21, we get 7 and a remainder of 13.
The number 7 becomes the next digit in our result. 
Result so far: 33359.47619047
The remainder is 13 after subtracting 147 from 160.
Since there are no more digits in the dividend, we add a zero to the remainder making it 130, and continue the process.

The final outcome is 33359.47619047, with a leftover of 1.3e-08.