We're dividing 646143 by 83 
The aim is to understand the frequency of 83 in 646143.

Advancing to step 1:
When dividing 6 by 83, we get 0 with a remainder of 6.
The next digit of our result is 0. 
Result so far: 0.0
Deduct 0 from 6 and we're left with 6.
Bring next digit (4) of the dividend behind the 6 and repeat the process: 64 / 83

On to step 2:
83 can be fit into 64 0 times, resulting in a remainder of 64.
Use 0 as the next digit of our solution. 
Result so far: 0.0
Deduct 0 from 64 and we're left with 64.
Grab the next digit (6) from the dividend, add it to 64, then carry on: 646 / 83

Let's proceed to step 3:
The number 83 fits into 646 7 times, leaving a remainder of 65.
The number 7 becomes the next digit in our result. 
Result so far: 7.0
The remainder is 65 after subtracting 581 from 646.
Fetch the next digit (1) from the dividend, attach it to 65 and continue: 651 / 83

Let's proceed to step 4:
If we divide 651 by 83, we get 7 and a remainder of 70.
Use 7 as the next digit of our solution. 
Result so far: 77.0
Deduct 581 from 651 and we're left with 70.
Grab the next digit (4) from the dividend, add it to 70, then carry on: 704 / 83

Step 5:
83 can be fit into 704 8 times, resulting in a remainder of 40.
The next digit of our result is 8. 
Result so far: 778.0
Subtract 664 from 704 to get 40.
Append the next digit (3) from the dividend to 40 and continue with: 403 / 83

Going ahead to step 6:
If we divide 403 by 83, we get 4 and a remainder of 71.
The next digit of our result is 4. 
Result so far: 7784.0
Subtract 332 from 403 to get 71.
Since there are no more digits in the dividend, we add a zero to the remainder making it 710, and continue the process.

On to step 7:
83 goes into 710 8 times with a remainder of 46.
Write down 8 as next digit of the result. 
Result so far: 7784.8
Deduct 664 from 710 and we're left with 46.
Since there are no more digits in the dividend, we add a zero to the remainder making it 460, and continue the process.

Step 8:
83 can be fit into 460 5 times, resulting in a remainder of 45.
The next digit of our result is 5. 
Result so far: 7784.85
Subtract 415 from 460 to get 45.
Since there are no more digits in the dividend, we add a zero to the remainder making it 450, and continue the process.

Step 9:
83 goes into 450 5 times with a remainder of 35.
Put 5 as the next digit of the answer. 
Result so far: 7784.855
If we take 415 away from 450, we end up with 35.
Since there are no more digits in the dividend, we add a zero to the remainder making it 350, and continue the process.

After the division, we end up with 7784.855 and a remainder of 0.0035.