391986 ÷ 8 
The aim is to understand the frequency of 8 in 391986.

Advancing to step 1:
When dividing 3 by 8, we get 0 with a remainder of 3.
Write down 0 as next digit of the result. 
Result so far: 0.0
The remainder is 3 after subtracting 0 from 3.
Grab the next digit (9) from the dividend, add it to 3, then carry on: 39 / 8

Let's proceed to step 2:
39 divided by 8 is 4 with a remainder of 7.
Use 4 as the next digit of our solution. 
Result so far: 4.0
If we take 32 away from 39, we end up with 7.
Append the next digit (1) from the dividend to 7 and continue with: 71 / 8

Going ahead to step 3:
If we divide 71 by 8, we get 8 and a remainder of 7.
The next digit of our result is 8. 
Result so far: 48.0
Deduct 64 from 71 and we're left with 7.
Fetch the next digit (9) from the dividend, attach it to 7 and continue: 79 / 8

Advancing to step 4:
8 can be fit into 79 9 times, resulting in a remainder of 7.
Record the quotient 9 as the next digit in the result. 
Result so far: 489.0
If we subtract 72 from 79, we get 7.
Include the next digit (8) from the dividend after 7, then repeat: 78 / 8

On to step 5:
78 divided by 8 is 9 with a remainder of 6.
The next digit of our result is 9. 
Result so far: 4899.0
The remainder is 6 after subtracting 72 from 78.
Bring next digit (6) of the dividend behind the 6 and repeat the process: 66 / 8

Let's proceed to step 6:
When dividing 66 by 8, we get 8 with a remainder of 2.
The next digit of our result is 8. 
Result so far: 48998.0
If we subtract 64 from 66, we get 2.
Since there are no more digits in the dividend, we add a zero to the remainder making it 20, and continue the process.

Advancing to step 7:
8 can be fit into 20 2 times, resulting in a remainder of 4.
Put 2 as the next digit of the answer. 
Result so far: 48998.2
Subtracting 16 from 20 leaves us with 4.
Since there are no more digits in the dividend, we add a zero to the remainder making it 40, and continue the process.

Going ahead to step 8:
When dividing 40 by 8, we get 5 with a remainder of 0.
Record the quotient 5 as the next digit in the result. 
Result so far: 48998.25
If we take 40 away from 40, we end up 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.

Let's proceed to step 9:
The number 8 fits into 0 0 times, leaving a remainder of 0.
Use 0 as the next digit of our solution. 
Result so far: 48998.25
If we take 0 away from 0, we end up 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.

Moving on to step 10:
When dividing 0 by 8, we get 0 with a remainder of 0.
Use 0 as the next digit of our solution. 
Result so far: 48998.25
If we subtract 0 from 0, we 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.

Our division results in 48998.25 with a remaining 0.0.