We look at the division of 400388 by 86 
The aim is to understand the frequency of 86 in 400388.

Let's proceed to step 1:
The number 86 fits into 4 0 times, leaving a remainder of 4.
Use 0 as the next digit of our solution. 
Result so far: 0.0
If we take 0 away from 4, we end up with 4.
Grab the next digit (0) from the dividend, add it to 4, then carry on: 40 / 86

On to step 2:
The number 86 fits into 40 0 times, leaving a remainder of 40.
The number 0 becomes the next digit in our result. 
Result so far: 0.0
Deduct 0 from 40 and we're left with 40.
Include the next digit (0) from the dividend after 40, then repeat: 400 / 86

On to step 3:
When dividing 400 by 86, we get 4 with a remainder of 56.
Write down 4 as next digit of the result. 
Result so far: 4.0
If we take 344 away from 400, we end up with 56.
Fetch the next digit (3) from the dividend, attach it to 56 and continue: 563 / 86

Advancing to step 4:
When dividing 563 by 86, we get 6 with a remainder of 47.
Put 6 as the next digit of the answer. 
Result so far: 46.0
The remainder is 47 after subtracting 516 from 563.
Include the next digit (8) from the dividend after 47, then repeat: 478 / 86

Advancing to step 5:
86 can be fit into 478 5 times, resulting in a remainder of 48.
Write down 5 as next digit of the result. 
Result so far: 465.0
Subtracting 430 from 478 leaves us with 48.
Bring next digit (8) of the dividend behind the 48 and repeat the process: 488 / 86

On to step 6:
488 divided by 86 is 5 with a remainder of 58.
The next digit of our result is 5. 
Result so far: 4655.0
Deduct 430 from 488 and we're left with 58.
Since there are no more digits in the dividend, we add a zero to the remainder making it 580, and continue the process.

Going ahead to step 7:
86 can be fit into 580 6 times, resulting in a remainder of 64.
Record the quotient 6 as the next digit in the result. 
Result so far: 4655.6
Subtract 516 from 580 to get 64.
Since there are no more digits in the dividend, we add a zero to the remainder making it 640, and continue the process.

Going ahead to step 8:
When dividing 640 by 86, we get 7 with a remainder of 38.
Put 7 as the next digit of the answer. 
Result so far: 4655.67
Subtract 602 from 640 to get 38.
Since there are no more digits in the dividend, we add a zero to the remainder making it 380, and continue the process.

Let's proceed to step 9:
86 goes into 380 4 times with a remainder of 36.
The number 4 becomes the next digit in our result. 
Result so far: 4655.674
The remainder is 36 after subtracting 344 from 380.
Since there are no more digits in the dividend, we add a zero to the remainder making it 360, and continue the process.

Going ahead to step 10:
86 goes into 360 4 times with a remainder of 16.
Write down 4 as next digit of the result. 
Result so far: 4655.6744
If we take 344 away from 360, we end up with 16.
Since there are no more digits in the dividend, we add a zero to the remainder making it 160, and continue the process.

After the division, we end up with 4655.6744 and a remainder of 0.00016.