391216 divided by 45 
The aim is to understand the frequency of 45 in 391216.

Advancing to step 1:
3 divided by 45 is 0 with a remainder of 3.
Put 0 as the next digit of the answer. 
Result so far: 0.0
The remainder is 3 after subtracting 0 from 3.
Include the next digit (9) from the dividend after 3, then repeat: 39 / 45

On to step 2:
45 can be fit into 39 0 times, resulting in a remainder of 39.
The next digit of our result is 0. 
Result so far: 0.0
Deduct 0 from 39 and we're left with 39.
Append the next digit (1) from the dividend to 39 and continue with: 391 / 45

Going ahead to step 3:
The number 45 fits into 391 8 times, leaving a remainder of 31.
Record the quotient 8 as the next digit in the result. 
Result so far: 8.0
Deduct 360 from 391 and we're left with 31.
Append the next digit (2) from the dividend to 31 and continue with: 312 / 45

On to step 4:
If we divide 312 by 45, we get 6 and a remainder of 42.
Write down 6 as next digit of the result. 
Result so far: 86.0
Subtract 270 from 312 to get 42.
Take the next digit (1) from the dividend and append it to 42, then repeat: 421 / 45

Moving on to step 5:
421 divided by 45 is 9 with a remainder of 16.
The next digit of our result is 9. 
Result so far: 869.0
If we subtract 405 from 421, we get 16.
Fetch the next digit (6) from the dividend, attach it to 16 and continue: 166 / 45

Advancing to step 6:
If we divide 166 by 45, we get 3 and a remainder of 31.
Record the quotient 3 as the next digit in the result. 
Result so far: 8693.0
If we take 135 away from 166, we end up with 31.
Since there are no more digits in the dividend, we add a zero to the remainder making it 310, and continue the process.

Let's proceed to step 7:
45 can be fit into 310 6 times, resulting in a remainder of 40.
Use 6 as the next digit of our solution. 
Result so far: 8693.6
If we take 270 away from 310, we end up with 40.
Since there are no more digits in the dividend, we add a zero to the remainder making it 400, and continue the process.

Going ahead to step 8:
45 goes into 400 8 times with a remainder of 40.
Put 8 as the next digit of the answer. 
Result so far: 8693.68
Deduct 360 from 400 and we're left with 40.
Since there are no more digits in the dividend, we add a zero to the remainder making it 400, and continue the process.

Going ahead to step 9:
The number 45 fits into 400 8 times, leaving a remainder of 40.
Write down 8 as next digit of the result. 
Result so far: 8693.688
The remainder is 40 after subtracting 360 from 400.
Since there are no more digits in the dividend, we add a zero to the remainder making it 400, and continue the process.

After the division, we end up with 8693.688 and a remainder of 0.004.