90412601 ÷ 404 
The aim is to understand the frequency of 404 in 90412601.

Let's proceed to step 1:
If we divide 9 by 404, we get 0 and a remainder of 9.
Record the quotient 0 as the next digit in the result. 
Result so far: 0.0
Deduct 0 from 9 and we're left with 9.
Bring next digit (0) of the dividend behind the 9 and repeat the process: 90 / 404

Going ahead to step 2:
The number 404 fits into 90 0 times, leaving a remainder of 90.
The number 0 becomes the next digit in our result. 
Result so far: 0.0
Deduct 0 from 90 and we're left with 90.
Include the next digit (4) from the dividend after 90, then repeat: 904 / 404

Step 3:
904 divided by 404 is 2 with a remainder of 96.
Put 2 as the next digit of the answer. 
Result so far: 2.0
If we subtract 808 from 904, we get 96.
Append the next digit (1) from the dividend to 96 and continue with: 961 / 404

On to step 4:
404 can be fit into 961 2 times, resulting in a remainder of 153.
The next digit of our result is 2. 
Result so far: 22.0
Subtract 808 from 961 to get 153.
Bring next digit (2) of the dividend behind the 153 and repeat the process: 1532 / 404

Moving on to step 5:
The number 404 fits into 1532 3 times, leaving a remainder of 320.
Write down 3 as next digit of the result. 
Result so far: 223.0
If we subtract 1212 from 1532, we get 320.
Fetch the next digit (6) from the dividend, attach it to 320 and continue: 3206 / 404

Advancing to step 6:
If we divide 3206 by 404, we get 7 and a remainder of 378.
The number 7 becomes the next digit in our result. 
Result so far: 2237.0
If we take 2828 away from 3206, we end up with 378.
Bring next digit (0) of the dividend behind the 378 and repeat the process: 3780 / 404

Advancing to step 7:
The number 404 fits into 3780 9 times, leaving a remainder of 144.
Put 9 as the next digit of the answer. 
Result so far: 22379.0
The remainder is 144 after subtracting 3636 from 3780.
Grab the next digit (1) from the dividend, add it to 144, then carry on: 1441 / 404

Advancing to step 8:
404 can be fit into 1441 3 times, resulting in a remainder of 229.
Record the quotient 3 as the next digit in the result. 
Result so far: 223793.0
Deduct 1212 from 1441 and we're left with 229.
Since there are no more digits in the dividend, we add a zero to the remainder making it 2290, and continue the process.

On to step 9:
When dividing 2290 by 404, we get 5 with a remainder of 270.
Put 5 as the next digit of the answer. 
Result so far: 223793.5
Deduct 2020 from 2290 and we're left with 270.
Since there are no more digits in the dividend, we add a zero to the remainder making it 2700, and continue the process.

Moving on to step 10:
404 can be fit into 2700 6 times, resulting in a remainder of 276.
The number 6 becomes the next digit in our result. 
Result so far: 223793.56
Subtracting 2424 from 2700 leaves us with 276.
Since there are no more digits in the dividend, we add a zero to the remainder making it 2760, and continue the process.

Advancing to step 11:
2760 divided by 404 is 6 with a remainder of 336.
Use 6 as the next digit of our solution. 
Result so far: 223793.566
Subtracting 2424 from 2760 leaves us with 336.
Since there are no more digits in the dividend, we add a zero to the remainder making it 3360, and continue the process.

After the division, we end up with 223793.566 and a remainder of 0.0336.