We're dividing 40491273 by 645 
The aim is to understand the frequency of 645 in 40491273.

Moving on to step 1:
645 can be fit into 4 0 times, resulting in a remainder of 4.
Use 0 as the next digit of our solution. 
Result so far: 0.0
If we take 0 away from 4, we end up with 4.
Append the next digit (0) from the dividend to 4 and continue with: 40 / 645

Step 2:
645 can be fit into 40 0 times, resulting in a remainder of 40.
The next digit of our result is 0. 
Result so far: 0.0
The remainder is 40 after subtracting 0 from 40.
Include the next digit (4) from the dividend after 40, then repeat: 404 / 645

Let's proceed to step 3:
If we divide 404 by 645, we get 0 and a remainder of 404.
The number 0 becomes the next digit in our result. 
Result so far: 0.0
The remainder is 404 after subtracting 0 from 404.
Include the next digit (9) from the dividend after 404, then repeat: 4049 / 645

Advancing to step 4:
645 can be fit into 4049 6 times, resulting in a remainder of 179.
Put 6 as the next digit of the answer. 
Result so far: 6.0
If we take 3870 away from 4049, we end up with 179.
Fetch the next digit (1) from the dividend, attach it to 179 and continue: 1791 / 645

Going ahead to step 5:
645 can be fit into 1791 2 times, resulting in a remainder of 501.
Record the quotient 2 as the next digit in the result. 
Result so far: 62.0
Deduct 1290 from 1791 and we're left with 501.
Grab the next digit (2) from the dividend, add it to 501, then carry on: 5012 / 645

Let's proceed to step 6:
If we divide 5012 by 645, we get 7 and a remainder of 497.
Record the quotient 7 as the next digit in the result. 
Result so far: 627.0
Subtracting 4515 from 5012 leaves us with 497.
Grab the next digit (7) from the dividend, add it to 497, then carry on: 4977 / 645

Step 7:
If we divide 4977 by 645, we get 7 and a remainder of 462.
The next digit of our result is 7. 
Result so far: 6277.0
The remainder is 462 after subtracting 4515 from 4977.
Take the next digit (3) from the dividend and append it to 462, then repeat: 4623 / 645

Let's proceed to step 8:
4623 divided by 645 is 7 with a remainder of 108.
The next digit of our result is 7. 
Result so far: 62777.0
If we subtract 4515 from 4623, we get 108.
Since there are no more digits in the dividend, we add a zero to the remainder making it 1080, and continue the process.

Moving on to step 9:
645 can be fit into 1080 1 times, resulting in a remainder of 435.
Put 1 as the next digit of the answer. 
Result so far: 62777.1
If we subtract 645 from 1080, we get 435.
Since there are no more digits in the dividend, we add a zero to the remainder making it 4350, and continue the process.

On to step 10:
645 goes into 4350 6 times with a remainder of 480.
Use 6 as the next digit of our solution. 
Result so far: 62777.16
Deduct 3870 from 4350 and we're left with 480.
Since there are no more digits in the dividend, we add a zero to the remainder making it 4800, and continue the process.

Step 11:
If we divide 4800 by 645, we get 7 and a remainder of 285.
Use 7 as the next digit of our solution. 
Result so far: 62777.167
Subtracting 4515 from 4800 leaves us with 285.
Since there are no more digits in the dividend, we add a zero to the remainder making it 2850, and continue the process.

Step 12:
2850 divided by 645 is 4 with a remainder of 270.
Record the quotient 4 as the next digit in the result. 
Result so far: 62777.1674
Subtract 2580 from 2850 to get 270.
Since there are no more digits in the dividend, we add a zero to the remainder making it 2700, and continue the process.

Step 13:
When dividing 2700 by 645, we get 4 with a remainder of 120.
The next digit of our result is 4. 
Result so far: 62777.16744
If we subtract 2580 from 2700, we get 120.
Since there are no more digits in the dividend, we add a zero to the remainder making it 1200, and continue the process.

The final result is 62777.16744 with a remainder of 0.00012.