We look at the division of 85109590 by 669 
The aim is to understand the frequency of 669 in 85109590.

On to step 1:
The number 669 fits into 8 0 times, leaving a remainder of 8.
The next digit of our result is 0. 
Result so far: 0.0
Subtract 0 from 8 to get 8.
Append the next digit (5) from the dividend to 8 and continue with: 85 / 669

Moving on to step 2:
If we divide 85 by 669, we get 0 and a remainder of 85.
Record the quotient 0 as the next digit in the result. 
Result so far: 0.0
Subtracting 0 from 85 leaves us with 85.
Include the next digit (1) from the dividend after 85, then repeat: 851 / 669

On to step 3:
669 goes into 851 1 times with a remainder of 182.
Use 1 as the next digit of our solution. 
Result so far: 1.0
Subtracting 669 from 851 leaves us with 182.
Append the next digit (0) from the dividend to 182 and continue with: 1820 / 669

Let's proceed to step 4:
When dividing 1820 by 669, we get 2 with a remainder of 482.
Use 2 as the next digit of our solution. 
Result so far: 12.0
If we take 1338 away from 1820, we end up with 482.
Take the next digit (9) from the dividend and append it to 482, then repeat: 4829 / 669

Let's proceed to step 5:
669 goes into 4829 7 times with a remainder of 146.
Record the quotient 7 as the next digit in the result. 
Result so far: 127.0
If we subtract 4683 from 4829, we get 146.
Bring next digit (5) of the dividend behind the 146 and repeat the process: 1465 / 669

Let's proceed to step 6:
1465 divided by 669 is 2 with a remainder of 127.
Put 2 as the next digit of the answer. 
Result so far: 1272.0
If we subtract 1338 from 1465, we get 127.
Fetch the next digit (9) from the dividend, attach it to 127 and continue: 1279 / 669

Moving on to step 7:
669 can be fit into 1279 1 times, resulting in a remainder of 610.
Record the quotient 1 as the next digit in the result. 
Result so far: 12721.0
Deduct 669 from 1279 and we're left with 610.
Append the next digit (0) from the dividend to 610 and continue with: 6100 / 669

Let's proceed to step 8:
If we divide 6100 by 669, we get 9 and a remainder of 79.
Record the quotient 9 as the next digit in the result. 
Result so far: 127219.0
If we subtract 6021 from 6100, we get 79.
Since there are no more digits in the dividend, we add a zero to the remainder making it 790, and continue the process.

Let's proceed to step 9:
The number 669 fits into 790 1 times, leaving a remainder of 121.
Put 1 as the next digit of the answer. 
Result so far: 127219.1
Subtract 669 from 790 to get 121.
Since there are no more digits in the dividend, we add a zero to the remainder making it 1210, and continue the process.

Going ahead to step 10:
When dividing 1210 by 669, we get 1 with a remainder of 541.
Put 1 as the next digit of the answer. 
Result so far: 127219.11
The remainder is 541 after subtracting 669 from 1210.
Since there are no more digits in the dividend, we add a zero to the remainder making it 5410, and continue the process.

After the division, we end up with 127219.11 and a remainder of 0.541.