Let's divide 90485717 by 409
The aim is to understand the frequency of 409 in 90485717.

Going ahead to step 1:
If we divide 9 by 409, we get 0 and a remainder of 9.
The next digit of our result is 0. 
Result so far: 0.0
Subtract 0 from 9 to get 9.
Fetch the next digit (0) from the dividend, attach it to 9 and continue: 90 / 409

Moving on to step 2:
When dividing 90 by 409, we get 0 with a remainder of 90.
The next digit of our result is 0. 
Result so far: 0.0
If we subtract 0 from 90, we get 90.
Append the next digit (4) from the dividend to 90 and continue with: 904 / 409

On to step 3:
If we divide 904 by 409, we get 2 and a remainder of 86.
Use 2 as the next digit of our solution. 
Result so far: 2.0
The remainder is 86 after subtracting 818 from 904.
Fetch the next digit (8) from the dividend, attach it to 86 and continue: 868 / 409

Step 4:
409 can be fit into 868 2 times, resulting in a remainder of 50.
Write down 2 as next digit of the result. 
Result so far: 22.0
The remainder is 50 after subtracting 818 from 868.
Take the next digit (5) from the dividend and append it to 50, then repeat: 505 / 409

On to step 5:
When dividing 505 by 409, we get 1 with a remainder of 96.
Record the quotient 1 as the next digit in the result. 
Result so far: 221.0
Deduct 409 from 505 and we're left with 96.
Append the next digit (7) from the dividend to 96 and continue with: 967 / 409

Let's proceed to step 6:
The number 409 fits into 967 2 times, leaving a remainder of 149.
Use 2 as the next digit of our solution. 
Result so far: 2212.0
If we take 818 away from 967, we end up with 149.
Take the next digit (1) from the dividend and append it to 149, then repeat: 1491 / 409

Let's proceed to step 7:
409 can be fit into 1491 3 times, resulting in a remainder of 264.
Record the quotient 3 as the next digit in the result. 
Result so far: 22123.0
Deduct 1227 from 1491 and we're left with 264.
Grab the next digit (7) from the dividend, add it to 264, then carry on: 2647 / 409

Step 8:
If we divide 2647 by 409, we get 6 and a remainder of 193.
Put 6 as the next digit of the answer. 
Result so far: 221236.0
If we subtract 2454 from 2647, we get 193.
Since there are no more digits in the dividend, we add a zero to the remainder making it 1930, and continue the process.

Let's proceed to step 9:
When dividing 1930 by 409, we get 4 with a remainder of 294.
Write down 4 as next digit of the result. 
Result so far: 221236.4
The remainder is 294 after subtracting 1636 from 1930.
Since there are no more digits in the dividend, we add a zero to the remainder making it 2940, and continue the process.

Moving on to step 10:
409 goes into 2940 7 times with a remainder of 77.
Record the quotient 7 as the next digit in the result. 
Result so far: 221236.47
The remainder is 77 after subtracting 2863 from 2940.
Since there are no more digits in the dividend, we add a zero to the remainder making it 770, and continue the process.

Step 11:
409 can be fit into 770 1 times, resulting in a remainder of 361.
Put 1 as the next digit of the answer. 
Result so far: 221236.471
The remainder is 361 after subtracting 409 from 770.
Since there are no more digits in the dividend, we add a zero to the remainder making it 3610, and continue the process.

Step 12:
The number 409 fits into 3610 8 times, leaving a remainder of 338.
Write down 8 as next digit of the result. 
Result so far: 221236.4718
If we take 3272 away from 3610, we end up with 338.
Since there are no more digits in the dividend, we add a zero to the remainder making it 3380, and continue the process.

Step 13:
3380 divided by 409 is 8 with a remainder of 108.
Put 8 as the next digit of the answer. 
Result so far: 221236.47188
Subtracting 3272 from 3380 leaves us with 108.
Since there are no more digits in the dividend, we add a zero to the remainder making it 1080, and continue the process.

The final result is 221236.47188 with a remainder of 0.000108.