We look at the division of 21753393 by 807 
The aim is to understand the frequency of 807 in 21753393.

Advancing to step 1:
When dividing 2 by 807, we get 0 with a remainder of 2.
Use 0 as the next digit of our solution. 
Result so far: 0.0
Subtracting 0 from 2 leaves us with 2.
Include the next digit (1) from the dividend after 2, then repeat: 21 / 807

Step 2:
When dividing 21 by 807, we get 0 with a remainder of 21.
The number 0 becomes the next digit in our result. 
Result so far: 0.0
Subtract 0 from 21 to get 21.
Take the next digit (7) from the dividend and append it to 21, then repeat: 217 / 807

Going ahead to step 3:
217 divided by 807 is 0 with a remainder of 217.
The number 0 becomes the next digit in our result. 
Result so far: 0.0
Subtract 0 from 217 to get 217.
Include the next digit (5) from the dividend after 217, then repeat: 2175 / 807

Moving on to step 4:
If we divide 2175 by 807, we get 2 and a remainder of 561.
Use 2 as the next digit of our solution. 
Result so far: 2.0
If we subtract 1614 from 2175, we get 561.
Append the next digit (3) from the dividend to 561 and continue with: 5613 / 807

Let's proceed to step 5:
5613 divided by 807 is 6 with a remainder of 771.
Use 6 as the next digit of our solution. 
Result so far: 26.0
Subtracting 4842 from 5613 leaves us with 771.
Append the next digit (3) from the dividend to 771 and continue with: 7713 / 807

Step 6:
807 goes into 7713 9 times with a remainder of 450.
The number 9 becomes the next digit in our result. 
Result so far: 269.0
If we subtract 7263 from 7713, we get 450.
Include the next digit (9) from the dividend after 450, then repeat: 4509 / 807

Going ahead to step 7:
The number 807 fits into 4509 5 times, leaving a remainder of 474.
The number 5 becomes the next digit in our result. 
Result so far: 2695.0
Subtract 4035 from 4509 to get 474.
Include the next digit (3) from the dividend after 474, then repeat: 4743 / 807

Step 8:
4743 divided by 807 is 5 with a remainder of 708.
Record the quotient 5 as the next digit in the result. 
Result so far: 26955.0
If we take 4035 away from 4743, we end up with 708.
Since there are no more digits in the dividend, we add a zero to the remainder making it 7080, and continue the process.

Advancing to step 9:
7080 divided by 807 is 8 with a remainder of 624.
Record the quotient 8 as the next digit in the result. 
Result so far: 26955.8
If we take 6456 away from 7080, we end up with 624.
Since there are no more digits in the dividend, we add a zero to the remainder making it 6240, and continue the process.

On to step 10:
6240 divided by 807 is 7 with a remainder of 591.
The number 7 becomes the next digit in our result. 
Result so far: 26955.87
If we subtract 5649 from 6240, we get 591.
Since there are no more digits in the dividend, we add a zero to the remainder making it 5910, and continue the process.

Moving on to step 11:
807 can be fit into 5910 7 times, resulting in a remainder of 261.
Record the quotient 7 as the next digit in the result. 
Result so far: 26955.877
If we take 5649 away from 5910, we end up with 261.
Since there are no more digits in the dividend, we add a zero to the remainder making it 2610, and continue the process.

After the division, we end up with 26955.877 and a remainder of 0.0261.