We're dividing 399217 by 77 
The aim is to understand the frequency of 77 in 399217.

Advancing to step 1:
If we divide 3 by 77, we get 0 and a remainder of 3.
The number 0 becomes the next digit in our result. 
Result so far: 0.0
Subtracting 0 from 3 leaves us with 3.
Take the next digit (9) from the dividend and append it to 3, then repeat: 39 / 77

Moving on to step 2:
When dividing 39 by 77, we get 0 with a remainder of 39.
Record the quotient 0 as the next digit in the result. 
Result so far: 0.0
Subtract 0 from 39 to get 39.
Fetch the next digit (9) from the dividend, attach it to 39 and continue: 399 / 77

Step 3:
When dividing 399 by 77, we get 5 with a remainder of 14.
Use 5 as the next digit of our solution. 
Result so far: 5.0
Subtracting 385 from 399 leaves us with 14.
Include the next digit (2) from the dividend after 14, then repeat: 142 / 77

Advancing to step 4:
142 divided by 77 is 1 with a remainder of 65.
Write down 1 as next digit of the result. 
Result so far: 51.0
If we subtract 77 from 142, we get 65.
Take the next digit (1) from the dividend and append it to 65, then repeat: 651 / 77

Going ahead to step 5:
77 goes into 651 8 times with a remainder of 35.
Write down 8 as next digit of the result. 
Result so far: 518.0
The remainder is 35 after subtracting 616 from 651.
Include the next digit (7) from the dividend after 35, then repeat: 357 / 77

Advancing to step 6:
If we divide 357 by 77, we get 4 and a remainder of 49.
The number 4 becomes the next digit in our result. 
Result so far: 5184.0
The remainder is 49 after subtracting 308 from 357.
Since there are no more digits in the dividend, we add a zero to the remainder making it 490, and continue the process.

On to step 7:
490 divided by 77 is 6 with a remainder of 28.
Record the quotient 6 as the next digit in the result. 
Result so far: 5184.6
If we subtract 462 from 490, we get 28.
Since there are no more digits in the dividend, we add a zero to the remainder making it 280, and continue the process.

Let's proceed to step 8:
77 can be fit into 280 3 times, resulting in a remainder of 49.
The number 3 becomes the next digit in our result. 
Result so far: 5184.63
If we take 231 away from 280, we end up with 49.
Since there are no more digits in the dividend, we add a zero to the remainder making it 490, and continue the process.

Advancing to step 9:
If we divide 490 by 77, we get 6 and a remainder of 28.
Record the quotient 6 as the next digit in the result. 
Result so far: 5184.636
Subtracting 462 from 490 leaves us 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.

Going ahead to step 10:
77 goes into 280 3 times with a remainder of 49.
Put 3 as the next digit of the answer. 
Result so far: 5184.6363
Deduct 231 from 280 and we're left with 49.
Since there are no more digits in the dividend, we add a zero to the remainder making it 490, and continue the process.

Going ahead to step 11:
490 divided by 77 is 6 with a remainder of 28.
Put 6 as the next digit of the answer. 
Result so far: 5184.63636
Subtract 462 from 490 to get 28.
Since there are no more digits in the dividend, we add a zero to the remainder making it 280, and continue the process.

Step 12:
If we divide 280 by 77, we get 3 and a remainder of 49.
Record the quotient 3 as the next digit in the result. 
Result so far: 5184.636363
The remainder is 49 after subtracting 231 from 280.
Since there are no more digits in the dividend, we add a zero to the remainder making it 490, and continue the process.

On to step 13:
If we divide 490 by 77, we get 6 and a remainder of 28.
The number 6 becomes the next digit in our result. 
Result so far: 5184.6363636
If we subtract 462 from 490, we get 28.
Since there are no more digits in the dividend, we add a zero to the remainder making it 280, and continue the process.

Step 14:
77 goes into 280 3 times with a remainder of 49.
Put 3 as the next digit of the answer. 
Result so far: 5184.63636363
Deduct 231 from 280 and we're left with 49.
Since there are no more digits in the dividend, we add a zero to the remainder making it 490, and continue the process.

The final result is 5184.63636363 with a remainder of 4.9e-08.