We divide 87884225 by 399
The aim is to understand the frequency of 399 in 87884225.

Advancing to step 1:
When dividing 8 by 399, we get 0 with a remainder of 8.
Use 0 as the next digit of our solution. 
Result so far: 0.0
Subtract 0 from 8 to get 8.
Include the next digit (7) from the dividend after 8, then repeat: 87 / 399

Going ahead to step 2:
399 goes into 87 0 times with a remainder of 87.
The number 0 becomes the next digit in our result. 
Result so far: 0.0
The remainder is 87 after subtracting 0 from 87.
Take the next digit (8) from the dividend and append it to 87, then repeat: 878 / 399

On to step 3:
878 divided by 399 is 2 with a remainder of 80.
The number 2 becomes the next digit in our result. 
Result so far: 2.0
If we take 798 away from 878, we end up with 80.
Append the next digit (8) from the dividend to 80 and continue with: 808 / 399

Step 4:
The number 399 fits into 808 2 times, leaving a remainder of 10.
Record the quotient 2 as the next digit in the result. 
Result so far: 22.0
Deduct 798 from 808 and we're left with 10.
Fetch the next digit (4) from the dividend, attach it to 10 and continue: 104 / 399

Moving on to step 5:
The number 399 fits into 104 0 times, leaving a remainder of 104.
The next digit of our result is 0. 
Result so far: 220.0
If we take 0 away from 104, we end up with 104.
Include the next digit (2) from the dividend after 104, then repeat: 1042 / 399

Let's proceed to step 6:
When dividing 1042 by 399, we get 2 with a remainder of 244.
The number 2 becomes the next digit in our result. 
Result so far: 2202.0
Subtract 798 from 1042 to get 244.
Append the next digit (2) from the dividend to 244 and continue with: 2442 / 399

On to step 7:
If we divide 2442 by 399, we get 6 and a remainder of 48.
The number 6 becomes the next digit in our result. 
Result so far: 22026.0
If we take 2394 away from 2442, we end up with 48.
Grab the next digit (5) from the dividend, add it to 48, then carry on: 485 / 399

On to step 8:
399 goes into 485 1 times with a remainder of 86.
The number 1 becomes the next digit in our result. 
Result so far: 220261.0
Subtract 399 from 485 to get 86.
Since there are no more digits in the dividend, we add a zero to the remainder making it 860, and continue the process.

Moving on to step 9:
860 divided by 399 is 2 with a remainder of 62.
The number 2 becomes the next digit in our result. 
Result so far: 220261.2
Subtracting 798 from 860 leaves us with 62.
Since there are no more digits in the dividend, we add a zero to the remainder making it 620, and continue the process.

Step 10:
399 goes into 620 1 times with a remainder of 221.
Record the quotient 1 as the next digit in the result. 
Result so far: 220261.21
Subtract 399 from 620 to get 221.
Since there are no more digits in the dividend, we add a zero to the remainder making it 2210, and continue the process.

On to step 11:
399 goes into 2210 5 times with a remainder of 215.
Use 5 as the next digit of our solution. 
Result so far: 220261.215
If we take 1995 away from 2210, we end up with 215.
Since there are no more digits in the dividend, we add a zero to the remainder making it 2150, and continue the process.

Let's proceed to step 12:
399 goes into 2150 5 times with a remainder of 155.
The next digit of our result is 5. 
Result so far: 220261.2155
If we take 1995 away from 2150, we end up with 155.
Since there are no more digits in the dividend, we add a zero to the remainder making it 1550, and continue the process.

Our division results in 220261.2155 with a remaining 0.00155.