We look at the division of 66860163 by 623 
The aim is to understand the frequency of 623 in 66860163.

Going ahead to step 1:
The number 623 fits into 6 0 times, leaving a remainder of 6.
Use 0 as the next digit of our solution. 
Result so far: 0.0
If we subtract 0 from 6, we get 6.
Grab the next digit (6) from the dividend, add it to 6, then carry on: 66 / 623

Advancing to step 2:
623 goes into 66 0 times with a remainder of 66.
The number 0 becomes the next digit in our result. 
Result so far: 0.0
The remainder is 66 after subtracting 0 from 66.
Include the next digit (8) from the dividend after 66, then repeat: 668 / 623

On to step 3:
When dividing 668 by 623, we get 1 with a remainder of 45.
Put 1 as the next digit of the answer. 
Result so far: 1.0
If we subtract 623 from 668, we get 45.
Take the next digit (6) from the dividend and append it to 45, then repeat: 456 / 623

Going ahead to step 4:
456 divided by 623 is 0 with a remainder of 456.
Write down 0 as next digit of the result. 
Result so far: 10.0
If we take 0 away from 456, we end up with 456.
Append the next digit (0) from the dividend to 456 and continue with: 4560 / 623

On to step 5:
If we divide 4560 by 623, we get 7 and a remainder of 199.
Record the quotient 7 as the next digit in the result. 
Result so far: 107.0
The remainder is 199 after subtracting 4361 from 4560.
Bring next digit (1) of the dividend behind the 199 and repeat the process: 1991 / 623

On to step 6:
623 can be fit into 1991 3 times, resulting in a remainder of 122.
Put 3 as the next digit of the answer. 
Result so far: 1073.0
If we subtract 1869 from 1991, we get 122.
Append the next digit (6) from the dividend to 122 and continue with: 1226 / 623

On to step 7:
623 can be fit into 1226 1 times, resulting in a remainder of 603.
Put 1 as the next digit of the answer. 
Result so far: 10731.0
Subtract 623 from 1226 to get 603.
Grab the next digit (3) from the dividend, add it to 603, then carry on: 6033 / 623

On to step 8:
The number 623 fits into 6033 9 times, leaving a remainder of 426.
The number 9 becomes the next digit in our result. 
Result so far: 107319.0
If we take 5607 away from 6033, we end up with 426.
Since there are no more digits in the dividend, we add a zero to the remainder making it 4260, and continue the process.

On to step 9:
4260 divided by 623 is 6 with a remainder of 522.
The next digit of our result is 6. 
Result so far: 107319.6
Deduct 3738 from 4260 and we're left with 522.
Since there are no more digits in the dividend, we add a zero to the remainder making it 5220, and continue the process.

Let's proceed to step 10:
623 can be fit into 5220 8 times, resulting in a remainder of 236.
Write down 8 as next digit of the result. 
Result so far: 107319.68
The remainder is 236 after subtracting 4984 from 5220.
Since there are no more digits in the dividend, we add a zero to the remainder making it 2360, and continue the process.

Going ahead to step 11:
When dividing 2360 by 623, we get 3 with a remainder of 491.
Put 3 as the next digit of the answer. 
Result so far: 107319.683
Subtract 1869 from 2360 to get 491.
Since there are no more digits in the dividend, we add a zero to the remainder making it 4910, and continue the process.

Step 12:
The number 623 fits into 4910 7 times, leaving a remainder of 549.
The number 7 becomes the next digit in our result. 
Result so far: 107319.6837
If we subtract 4361 from 4910, we get 549.
Since there are no more digits in the dividend, we add a zero to the remainder making it 5490, and continue the process.

On to step 13:
The number 623 fits into 5490 8 times, leaving a remainder of 506.
Put 8 as the next digit of the answer. 
Result so far: 107319.68378
If we subtract 4984 from 5490, we get 506.
Since there are no more digits in the dividend, we add a zero to the remainder making it 5060, and continue the process.

Going ahead to step 14:
5060 divided by 623 is 8 with a remainder of 76.
Record the quotient 8 as the next digit in the result. 
Result so far: 107319.683788
Subtract 4984 from 5060 to get 76.
Since there are no more digits in the dividend, we add a zero to the remainder making it 760, and continue the process.

The final outcome is 107319.683788, with a leftover of 7.6e-06.