87586123 ÷ 804 
The aim is to understand the frequency of 804 in 87586123.

Advancing to step 1:
If we divide 8 by 804, we get 0 and a remainder of 8.
Record the quotient 0 as the next digit in the result. 
Result so far: 0.0
If we take 0 away from 8, we end up with 8.
Take the next digit (7) from the dividend and append it to 8, then repeat: 87 / 804

On to step 2:
The number 804 fits into 87 0 times, leaving a remainder of 87.
Use 0 as the next digit of our solution. 
Result so far: 0.0
Deduct 0 from 87 and we're left with 87.
Take the next digit (5) from the dividend and append it to 87, then repeat: 875 / 804

Moving on to step 3:
804 goes into 875 1 times with a remainder of 71.
The next digit of our result is 1. 
Result so far: 1.0
Subtracting 804 from 875 leaves us with 71.
Append the next digit (8) from the dividend to 71 and continue with: 718 / 804

Let's proceed to step 4:
The number 804 fits into 718 0 times, leaving a remainder of 718.
Record the quotient 0 as the next digit in the result. 
Result so far: 10.0
The remainder is 718 after subtracting 0 from 718.
Bring next digit (6) of the dividend behind the 718 and repeat the process: 7186 / 804

Going ahead to step 5:
804 can be fit into 7186 8 times, resulting in a remainder of 754.
Put 8 as the next digit of the answer. 
Result so far: 108.0
If we take 6432 away from 7186, we end up with 754.
Bring next digit (1) of the dividend behind the 754 and repeat the process: 7541 / 804

Advancing to step 6:
804 can be fit into 7541 9 times, resulting in a remainder of 305.
The number 9 becomes the next digit in our result. 
Result so far: 1089.0
If we take 7236 away from 7541, we end up with 305.
Bring next digit (2) of the dividend behind the 305 and repeat the process: 3052 / 804

Moving on to step 7:
The number 804 fits into 3052 3 times, leaving a remainder of 640.
Put 3 as the next digit of the answer. 
Result so far: 10893.0
Subtract 2412 from 3052 to get 640.
Append the next digit (3) from the dividend to 640 and continue with: 6403 / 804

Step 8:
The number 804 fits into 6403 7 times, leaving a remainder of 775.
Record the quotient 7 as the next digit in the result. 
Result so far: 108937.0
Subtracting 5628 from 6403 leaves us with 775.
Since there are no more digits in the dividend, we add a zero to the remainder making it 7750, and continue the process.

Step 9:
If we divide 7750 by 804, we get 9 and a remainder of 514.
Record the quotient 9 as the next digit in the result. 
Result so far: 108937.9
If we take 7236 away from 7750, we end up with 514.
Since there are no more digits in the dividend, we add a zero to the remainder making it 5140, and continue the process.

Advancing to step 10:
804 goes into 5140 6 times with a remainder of 316.
Record the quotient 6 as the next digit in the result. 
Result so far: 108937.96
Deduct 4824 from 5140 and we're left with 316.
Since there are no more digits in the dividend, we add a zero to the remainder making it 3160, and continue the process.

Advancing to step 11:
3160 divided by 804 is 3 with a remainder of 748.
Use 3 as the next digit of our solution. 
Result so far: 108937.963
Subtracting 2412 from 3160 leaves us with 748.
Since there are no more digits in the dividend, we add a zero to the remainder making it 7480, and continue the process.

Advancing to step 12:
7480 divided by 804 is 9 with a remainder of 244.
Put 9 as the next digit of the answer. 
Result so far: 108937.9639
Subtracting 7236 from 7480 leaves us with 244.
Since there are no more digits in the dividend, we add a zero to the remainder making it 2440, and continue the process.

Advancing to step 13:
When dividing 2440 by 804, we get 3 with a remainder of 28.
Write down 3 as next digit of the result. 
Result so far: 108937.96393
If we take 2412 away from 2440, we end up with 28.
Since there are no more digits in the dividend, we add a zero to the remainder making it 280, and continue the process.

Moving on to step 14:
If we divide 280 by 804, we get 0 and a remainder of 280.
Record the quotient 0 as the next digit in the result. 
Result so far: 108937.96393
Subtracting 0 from 280 leaves us with 280.
Since there are no more digits in the dividend, we add a zero to the remainder making it 2800, and continue the process.

Step 15:
804 can be fit into 2800 3 times, resulting in a remainder of 388.
The next digit of our result is 3. 
Result so far: 108937.9639303
Subtract 2412 from 2800 to get 388.
Since there are no more digits in the dividend, we add a zero to the remainder making it 3880, and continue the process.

On to step 16:
804 goes into 3880 4 times with a remainder of 664.
Write down 4 as next digit of the result. 
Result so far: 108937.96393034
Subtract 3216 from 3880 to get 664.
Since there are no more digits in the dividend, we add a zero to the remainder making it 6640, and continue the process.

After the division, we end up with 108937.96393034 and a remainder of 6.64e-07.