Let's divide 19173187 by 661
The aim is to understand the frequency of 661 in 19173187.

Going ahead to step 1:
The number 661 fits into 1 0 times, leaving a remainder of 1.
Put 0 as the next digit of the answer. 
Result so far: 0.0
If we subtract 0 from 1, we get 1.
Bring next digit (9) of the dividend behind the 1 and repeat the process: 19 / 661

Step 2:
When dividing 19 by 661, we get 0 with a remainder of 19.
The number 0 becomes the next digit in our result. 
Result so far: 0.0
Subtracting 0 from 19 leaves us with 19.
Grab the next digit (1) from the dividend, add it to 19, then carry on: 191 / 661

Going ahead to step 3:
661 can be fit into 191 0 times, resulting in a remainder of 191.
Put 0 as the next digit of the answer. 
Result so far: 0.0
Subtracting 0 from 191 leaves us with 191.
Include the next digit (7) from the dividend after 191, then repeat: 1917 / 661

Going ahead to step 4:
If we divide 1917 by 661, we get 2 and a remainder of 595.
Put 2 as the next digit of the answer. 
Result so far: 2.0
Deduct 1322 from 1917 and we're left with 595.
Bring next digit (3) of the dividend behind the 595 and repeat the process: 5953 / 661

Moving on to step 5:
661 can be fit into 5953 9 times, resulting in a remainder of 4.
Write down 9 as next digit of the result. 
Result so far: 29.0
If we subtract 5949 from 5953, we get 4.
Append the next digit (1) from the dividend to 4 and continue with: 41 / 661

Step 6:
661 goes into 41 0 times with a remainder of 41.
Write down 0 as next digit of the result. 
Result so far: 290.0
Subtract 0 from 41 to get 41.
Fetch the next digit (8) from the dividend, attach it to 41 and continue: 418 / 661

Going ahead to step 7:
418 divided by 661 is 0 with a remainder of 418.
Put 0 as the next digit of the answer. 
Result so far: 2900.0
The remainder is 418 after subtracting 0 from 418.
Grab the next digit (7) from the dividend, add it to 418, then carry on: 4187 / 661

Let's proceed to step 8:
4187 divided by 661 is 6 with a remainder of 221.
Use 6 as the next digit of our solution. 
Result so far: 29006.0
Subtracting 3966 from 4187 leaves us with 221.
Since there are no more digits in the dividend, we add a zero to the remainder making it 2210, and continue the process.

Moving on to step 9:
661 can be fit into 2210 3 times, resulting in a remainder of 227.
Put 3 as the next digit of the answer. 
Result so far: 29006.3
If we take 1983 away from 2210, we end up with 227.
Since there are no more digits in the dividend, we add a zero to the remainder making it 2270, and continue the process.

Advancing to step 10:
The number 661 fits into 2270 3 times, leaving a remainder of 287.
Put 3 as the next digit of the answer. 
Result so far: 29006.33
Deduct 1983 from 2270 and we're left with 287.
Since there are no more digits in the dividend, we add a zero to the remainder making it 2870, and continue the process.

The final result is 29006.33 with a remainder of 0.287.