86991932 ÷ 400 
The aim is to understand the frequency of 400 in 86991932.

Step 1:
The number 400 fits into 8 0 times, leaving a remainder of 8.
Use 0 as the next digit of our solution. 
Result so far: 0.0
The remainder is 8 after subtracting 0 from 8.
Fetch the next digit (6) from the dividend, attach it to 8 and continue: 86 / 400

Going ahead to step 2:
If we divide 86 by 400, we get 0 and a remainder of 86.
Write down 0 as next digit of the result. 
Result so far: 0.0
If we take 0 away from 86, we end up with 86.
Take the next digit (9) from the dividend and append it to 86, then repeat: 869 / 400

Let's proceed to step 3:
The number 400 fits into 869 2 times, leaving a remainder of 69.
Put 2 as the next digit of the answer. 
Result so far: 2.0
Subtract 800 from 869 to get 69.
Append the next digit (9) from the dividend to 69 and continue with: 699 / 400

Going ahead to step 4:
400 goes into 699 1 times with a remainder of 299.
The next digit of our result is 1. 
Result so far: 21.0
Subtracting 400 from 699 leaves us with 299.
Fetch the next digit (1) from the dividend, attach it to 299 and continue: 2991 / 400

Going ahead to step 5:
The number 400 fits into 2991 7 times, leaving a remainder of 191.
Use 7 as the next digit of our solution. 
Result so far: 217.0
If we take 2800 away from 2991, we end up with 191.
Grab the next digit (9) from the dividend, add it to 191, then carry on: 1919 / 400

Moving on to step 6:
400 can be fit into 1919 4 times, resulting in a remainder of 319.
Put 4 as the next digit of the answer. 
Result so far: 2174.0
If we take 1600 away from 1919, we end up with 319.
Include the next digit (3) from the dividend after 319, then repeat: 3193 / 400

Moving on to step 7:
The number 400 fits into 3193 7 times, leaving a remainder of 393.
The next digit of our result is 7. 
Result so far: 21747.0
The remainder is 393 after subtracting 2800 from 3193.
Fetch the next digit (2) from the dividend, attach it to 393 and continue: 3932 / 400

On to step 8:
The number 400 fits into 3932 9 times, leaving a remainder of 332.
The number 9 becomes the next digit in our result. 
Result so far: 217479.0
Deduct 3600 from 3932 and we're left with 332.
Since there are no more digits in the dividend, we add a zero to the remainder making it 3320, and continue the process.

Moving on to step 9:
If we divide 3320 by 400, we get 8 and a remainder of 120.
The next digit of our result is 8. 
Result so far: 217479.8
The remainder is 120 after subtracting 3200 from 3320.
Since there are no more digits in the dividend, we add a zero to the remainder making it 1200, and continue the process.

Moving on to step 10:
400 goes into 1200 3 times with a remainder of 0.
Use 3 as the next digit of our solution. 
Result so far: 217479.83
The remainder is 0 after subtracting 1200 from 1200.
Since there are no more digits in the dividend, we add a zero to the remainder making it 0, and continue the process.

Let's proceed to step 11:
If we divide 0 by 400, we get 0 and a remainder of 0.
The next digit of our result is 0. 
Result so far: 217479.83
Subtracting 0 from 0 leaves us with 0.
Since there are no more digits in the dividend, we add a zero to the remainder making it 0, and continue the process.

Going ahead to step 12:
400 goes into 0 0 times with a remainder of 0.
Use 0 as the next digit of our solution. 
Result so far: 217479.83
Subtract 0 from 0 to get 0.
Since there are no more digits in the dividend, we add a zero to the remainder making it 0, and continue the process.

The final result is 217479.83 with a remainder of 0.0.