66090885 ÷ 807 
The aim is to understand the frequency of 807 in 66090885.

Step 1:
6 divided by 807 is 0 with a remainder of 6.
Record the quotient 0 as the next digit in the result. 
Result so far: 0.0
Deduct 0 from 6 and we're left with 6.
Take the next digit (6) from the dividend and append it to 6, then repeat: 66 / 807

Going ahead to step 2:
807 can be fit into 66 0 times, resulting in a remainder of 66.
Put 0 as the next digit of the answer. 
Result so far: 0.0
If we take 0 away from 66, we end up with 66.
Bring next digit (0) of the dividend behind the 66 and repeat the process: 660 / 807

Let's proceed to step 3:
When dividing 660 by 807, we get 0 with a remainder of 660.
Use 0 as the next digit of our solution. 
Result so far: 0.0
Subtracting 0 from 660 leaves us with 660.
Fetch the next digit (9) from the dividend, attach it to 660 and continue: 6609 / 807

Step 4:
If we divide 6609 by 807, we get 8 and a remainder of 153.
The number 8 becomes the next digit in our result. 
Result so far: 8.0
Deduct 6456 from 6609 and we're left with 153.
Bring next digit (0) of the dividend behind the 153 and repeat the process: 1530 / 807

Let's proceed to step 5:
When dividing 1530 by 807, we get 1 with a remainder of 723.
Use 1 as the next digit of our solution. 
Result so far: 81.0
The remainder is 723 after subtracting 807 from 1530.
Grab the next digit (8) from the dividend, add it to 723, then carry on: 7238 / 807

Advancing to step 6:
807 can be fit into 7238 8 times, resulting in a remainder of 782.
Use 8 as the next digit of our solution. 
Result so far: 818.0
The remainder is 782 after subtracting 6456 from 7238.
Include the next digit (8) from the dividend after 782, then repeat: 7828 / 807

On to step 7:
7828 divided by 807 is 9 with a remainder of 565.
Put 9 as the next digit of the answer. 
Result so far: 8189.0
Subtract 7263 from 7828 to get 565.
Include the next digit (5) from the dividend after 565, then repeat: 5655 / 807

Going ahead to step 8:
5655 divided by 807 is 7 with a remainder of 6.
Record the quotient 7 as the next digit in the result. 
Result so far: 81897.0
If we subtract 5649 from 5655, 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.

Step 9:
If we divide 60 by 807, we get 0 and a remainder of 60.
Record the quotient 0 as the next digit in the result. 
Result so far: 81897.0
Subtract 0 from 60 to get 60.
Since there are no more digits in the dividend, we add a zero to the remainder making it 600, and continue the process.

Advancing to step 10:
If we divide 600 by 807, we get 0 and a remainder of 600.
The number 0 becomes the next digit in our result. 
Result so far: 81897.0
If we take 0 away from 600, we end up with 600.
Since there are no more digits in the dividend, we add a zero to the remainder making it 6000, and continue the process.

The quotient of the division is 81897.0, and the remainder is 0.6.