We're dividing 91384839 by 645 
The aim is to understand the frequency of 645 in 91384839.

Step 1:
645 can be fit into 9 0 times, resulting in a remainder of 9.
The next digit of our result is 0. 
Result so far: 0.0
Deduct 0 from 9 and we're left with 9.
Include the next digit (1) from the dividend after 9, then repeat: 91 / 645

On to step 2:
91 divided by 645 is 0 with a remainder of 91.
Write down 0 as next digit of the result. 
Result so far: 0.0
Subtract 0 from 91 to get 91.
Include the next digit (3) from the dividend after 91, then repeat: 913 / 645

Let's proceed to step 3:
The number 645 fits into 913 1 times, leaving a remainder of 268.
Use 1 as the next digit of our solution. 
Result so far: 1.0
If we take 645 away from 913, we end up with 268.
Fetch the next digit (8) from the dividend, attach it to 268 and continue: 2688 / 645

Advancing to step 4:
645 goes into 2688 4 times with a remainder of 108.
The number 4 becomes the next digit in our result. 
Result so far: 14.0
If we take 2580 away from 2688, we end up with 108.
Take the next digit (4) from the dividend and append it to 108, then repeat: 1084 / 645

On to step 5:
645 goes into 1084 1 times with a remainder of 439.
Write down 1 as next digit of the result. 
Result so far: 141.0
The remainder is 439 after subtracting 645 from 1084.
Grab the next digit (8) from the dividend, add it to 439, then carry on: 4398 / 645

Going ahead to step 6:
If we divide 4398 by 645, we get 6 and a remainder of 528.
Use 6 as the next digit of our solution. 
Result so far: 1416.0
Subtracting 3870 from 4398 leaves us with 528.
Take the next digit (3) from the dividend and append it to 528, then repeat: 5283 / 645

Let's proceed to step 7:
645 goes into 5283 8 times with a remainder of 123.
The next digit of our result is 8. 
Result so far: 14168.0
If we subtract 5160 from 5283, we get 123.
Grab the next digit (9) from the dividend, add it to 123, then carry on: 1239 / 645

Going ahead to step 8:
645 can be fit into 1239 1 times, resulting in a remainder of 594.
The next digit of our result is 1. 
Result so far: 141681.0
Subtract 645 from 1239 to get 594.
Since there are no more digits in the dividend, we add a zero to the remainder making it 5940, and continue the process.

Going ahead to step 9:
645 goes into 5940 9 times with a remainder of 135.
The next digit of our result is 9. 
Result so far: 141681.9
Subtracting 5805 from 5940 leaves us with 135.
Since there are no more digits in the dividend, we add a zero to the remainder making it 1350, and continue the process.

On to step 10:
1350 divided by 645 is 2 with a remainder of 60.
Write down 2 as next digit of the result. 
Result so far: 141681.92
Subtract 1290 from 1350 to get 60.
Since there are no more digits in the dividend, we add a zero to the remainder making it 600, and continue the process.

Going ahead to step 11:
When dividing 600 by 645, we get 0 with a remainder of 600.
The next digit of our result is 0. 
Result so far: 141681.92
If we take 0 away from 600, we end up with 600.
Since there are no more digits in the dividend, we add a zero to the remainder making it 6000, and continue the process.

Let's proceed to step 12:
If we divide 6000 by 645, we get 9 and a remainder of 195.
The next digit of our result is 9. 
Result so far: 141681.9209
If we take 5805 away from 6000, we end up with 195.
Since there are no more digits in the dividend, we add a zero to the remainder making it 1950, and continue the process.

Moving on to step 13:
1950 divided by 645 is 3 with a remainder of 15.
The number 3 becomes the next digit in our result. 
Result so far: 141681.92093
If we take 1935 away from 1950, we end up with 15.
Since there are no more digits in the dividend, we add a zero to the remainder making it 150, and continue the process.

Moving on to step 14:
The number 645 fits into 150 0 times, leaving a remainder of 150.
Put 0 as the next digit of the answer. 
Result so far: 141681.92093
If we subtract 0 from 150, we get 150.
Since there are no more digits in the dividend, we add a zero to the remainder making it 1500, and continue the process.

Going ahead to step 15:
The number 645 fits into 1500 2 times, leaving a remainder of 210.
The next digit of our result is 2. 
Result so far: 141681.9209302
Subtracting 1290 from 1500 leaves us with 210.
Since there are no more digits in the dividend, we add a zero to the remainder making it 2100, and continue the process.

Going ahead to step 16:
When dividing 2100 by 645, we get 3 with a remainder of 165.
Use 3 as the next digit of our solution. 
Result so far: 141681.92093023
If we subtract 1935 from 2100, we get 165.
Since there are no more digits in the dividend, we add a zero to the remainder making it 1650, and continue the process.

After the division, we end up with 141681.92093023 and a remainder of 1.65e-07.