We're dividing 71850999 by 660 
The aim is to understand the frequency of 660 in 71850999.

Advancing to step 1:
7 divided by 660 is 0 with a remainder of 7.
Write down 0 as next digit of the result. 
Result so far: 0.0
Subtract 0 from 7 to get 7.
Append the next digit (1) from the dividend to 7 and continue with: 71 / 660

Going ahead to step 2:
If we divide 71 by 660, we get 0 and a remainder of 71.
Record the quotient 0 as the next digit in the result. 
Result so far: 0.0
Subtracting 0 from 71 leaves us with 71.
Include the next digit (8) from the dividend after 71, then repeat: 718 / 660

Let's proceed to step 3:
The number 660 fits into 718 1 times, leaving a remainder of 58.
Use 1 as the next digit of our solution. 
Result so far: 1.0
If we subtract 660 from 718, we get 58.
Bring next digit (5) of the dividend behind the 58 and repeat the process: 585 / 660

On to step 4:
If we divide 585 by 660, we get 0 and a remainder of 585.
Use 0 as the next digit of our solution. 
Result so far: 10.0
Subtract 0 from 585 to get 585.
Fetch the next digit (0) from the dividend, attach it to 585 and continue: 5850 / 660

Let's proceed to step 5:
The number 660 fits into 5850 8 times, leaving a remainder of 570.
Write down 8 as next digit of the result. 
Result so far: 108.0
If we subtract 5280 from 5850, we get 570.
Bring next digit (9) of the dividend behind the 570 and repeat the process: 5709 / 660

Step 6:
660 goes into 5709 8 times with a remainder of 429.
Put 8 as the next digit of the answer. 
Result so far: 1088.0
Deduct 5280 from 5709 and we're left with 429.
Append the next digit (9) from the dividend to 429 and continue with: 4299 / 660

Going ahead to step 7:
660 can be fit into 4299 6 times, resulting in a remainder of 339.
The next digit of our result is 6. 
Result so far: 10886.0
If we subtract 3960 from 4299, we get 339.
Bring next digit (9) of the dividend behind the 339 and repeat the process: 3399 / 660

Let's proceed to step 8:
3399 divided by 660 is 5 with a remainder of 99.
Record the quotient 5 as the next digit in the result. 
Result so far: 108865.0
If we take 3300 away from 3399, we end up with 99.
Since there are no more digits in the dividend, we add a zero to the remainder making it 990, and continue the process.

On to step 9:
When dividing 990 by 660, we get 1 with a remainder of 330.
The number 1 becomes the next digit in our result. 
Result so far: 108865.1
Subtracting 660 from 990 leaves us with 330.
Since there are no more digits in the dividend, we add a zero to the remainder making it 3300, and continue the process.

On to step 10:
660 goes into 3300 5 times with a remainder of 0.
Record the quotient 5 as the next digit in the result. 
Result so far: 108865.15
If we take 3300 away from 3300, we end up with 0.
Since there are no more digits in the dividend, we add a zero to the remainder making it 0, and continue the process.

Going ahead to step 11:
The number 660 fits into 0 0 times, leaving a remainder of 0.
Write down 0 as next digit of the result. 
Result so far: 108865.15
Subtract 0 from 0 to get 0.
Since there are no more digits in the dividend, we add a zero to the remainder making it 0, and continue the process.

On to step 12:
When dividing 0 by 660, we get 0 with a remainder of 0.
The number 0 becomes the next digit in our result. 
Result so far: 108865.15
The remainder is 0 after subtracting 0 from 0.
Since there are no more digits in the dividend, we add a zero to the remainder making it 0, and continue the process.

Our division results in 108865.15 with a remaining 0.0.