We're dividing 10401999 by 604 
The aim is to understand the frequency of 604 in 10401999.

Advancing to step 1:
If we divide 1 by 604, we get 0 and a remainder of 1.
The next digit of our result is 0. 
Result so far: 0.0
Deduct 0 from 1 and we're left with 1.
Grab the next digit (0) from the dividend, add it to 1, then carry on: 10 / 604

Advancing to step 2:
The number 604 fits into 10 0 times, leaving a remainder of 10.
The number 0 becomes the next digit in our result. 
Result so far: 0.0
Subtract 0 from 10 to get 10.
Fetch the next digit (4) from the dividend, attach it to 10 and continue: 104 / 604

Moving on to step 3:
604 goes into 104 0 times with a remainder of 104.
Write down 0 as next digit of the result. 
Result so far: 0.0
Subtract 0 from 104 to get 104.
Include the next digit (0) from the dividend after 104, then repeat: 1040 / 604

Let's proceed to step 4:
1040 divided by 604 is 1 with a remainder of 436.
Put 1 as the next digit of the answer. 
Result so far: 1.0
Subtract 604 from 1040 to get 436.
Fetch the next digit (1) from the dividend, attach it to 436 and continue: 4361 / 604

Advancing to step 5:
4361 divided by 604 is 7 with a remainder of 133.
Use 7 as the next digit of our solution. 
Result so far: 17.0
Subtract 4228 from 4361 to get 133.
Include the next digit (9) from the dividend after 133, then repeat: 1339 / 604

Let's proceed to step 6:
1339 divided by 604 is 2 with a remainder of 131.
Record the quotient 2 as the next digit in the result. 
Result so far: 172.0
If we subtract 1208 from 1339, we get 131.
Bring next digit (9) of the dividend behind the 131 and repeat the process: 1319 / 604

Advancing to step 7:
The number 604 fits into 1319 2 times, leaving a remainder of 111.
The number 2 becomes the next digit in our result. 
Result so far: 1722.0
If we subtract 1208 from 1319, we get 111.
Append the next digit (9) from the dividend to 111 and continue with: 1119 / 604

On to step 8:
When dividing 1119 by 604, we get 1 with a remainder of 515.
Put 1 as the next digit of the answer. 
Result so far: 17221.0
If we take 604 away from 1119, we end up with 515.
Since there are no more digits in the dividend, we add a zero to the remainder making it 5150, and continue the process.

Step 9:
604 goes into 5150 8 times with a remainder of 318.
Use 8 as the next digit of our solution. 
Result so far: 17221.8
Subtract 4832 from 5150 to get 318.
Since there are no more digits in the dividend, we add a zero to the remainder making it 3180, and continue the process.

On to step 10:
When dividing 3180 by 604, we get 5 with a remainder of 160.
Record the quotient 5 as the next digit in the result. 
Result so far: 17221.85
If we subtract 3020 from 3180, we get 160.
Since there are no more digits in the dividend, we add a zero to the remainder making it 1600, and continue the process.

Going ahead to step 11:
When dividing 1600 by 604, we get 2 with a remainder of 392.
The next digit of our result is 2. 
Result so far: 17221.852
Subtract 1208 from 1600 to get 392.
Since there are no more digits in the dividend, we add a zero to the remainder making it 3920, and continue the process.

Moving on to step 12:
604 goes into 3920 6 times with a remainder of 296.
Use 6 as the next digit of our solution. 
Result so far: 17221.8526
If we take 3624 away from 3920, we end up with 296.
Since there are no more digits in the dividend, we add a zero to the remainder making it 2960, and continue the process.

Let's proceed to step 13:
The number 604 fits into 2960 4 times, leaving a remainder of 544.
Record the quotient 4 as the next digit in the result. 
Result so far: 17221.85264
If we subtract 2416 from 2960, we get 544.
Since there are no more digits in the dividend, we add a zero to the remainder making it 5440, and continue the process.

Moving on to step 14:
604 can be fit into 5440 9 times, resulting in a remainder of 4.
Put 9 as the next digit of the answer. 
Result so far: 17221.852649
If we subtract 5436 from 5440, we get 4.
Since there are no more digits in the dividend, we add a zero to the remainder making it 40, and continue the process.

Step 15:
40 divided by 604 is 0 with a remainder of 40.
The next digit of our result is 0. 
Result so far: 17221.852649
If we take 0 away from 40, we end up with 40.
Since there are no more digits in the dividend, we add a zero to the remainder making it 400, and continue the process.

On to step 16:
The number 604 fits into 400 0 times, leaving a remainder of 400.
Record the quotient 0 as the next digit in the result. 
Result so far: 17221.852649
Subtracting 0 from 400 leaves us with 400.
Since there are no more digits in the dividend, we add a zero to the remainder making it 4000, and continue the process.

Our division results in 17221.852649 with a remaining 4e-07.