We look at the division of 750557 by 45 
The aim is to understand the frequency of 45 in 750557.

On to step 1:
If we divide 7 by 45, we get 0 and a remainder of 7.
The number 0 becomes the next digit in our result. 
Result so far: 0.0
The remainder is 7 after subtracting 0 from 7.
Bring next digit (5) of the dividend behind the 7 and repeat the process: 75 / 45

Step 2:
When dividing 75 by 45, we get 1 with a remainder of 30.
The number 1 becomes the next digit in our result. 
Result so far: 1.0
Subtracting 45 from 75 leaves us with 30.
Take the next digit (0) from the dividend and append it to 30, then repeat: 300 / 45

Going ahead to step 3:
45 can be fit into 300 6 times, resulting in a remainder of 30.
Record the quotient 6 as the next digit in the result. 
Result so far: 16.0
The remainder is 30 after subtracting 270 from 300.
Grab the next digit (5) from the dividend, add it to 30, then carry on: 305 / 45

Going ahead to step 4:
The number 45 fits into 305 6 times, leaving a remainder of 35.
Put 6 as the next digit of the answer. 
Result so far: 166.0
If we take 270 away from 305, we end up with 35.
Take the next digit (5) from the dividend and append it to 35, then repeat: 355 / 45

Going ahead to step 5:
When dividing 355 by 45, we get 7 with a remainder of 40.
Write down 7 as next digit of the result. 
Result so far: 1667.0
The remainder is 40 after subtracting 315 from 355.
Include the next digit (7) from the dividend after 40, then repeat: 407 / 45

On to step 6:
407 divided by 45 is 9 with a remainder of 2.
The next digit of our result is 9. 
Result so far: 16679.0
The remainder is 2 after subtracting 405 from 407.
Since there are no more digits in the dividend, we add a zero to the remainder making it 20, and continue the process.

Moving on to step 7:
20 divided by 45 is 0 with a remainder of 20.
Write down 0 as next digit of the result. 
Result so far: 16679.0
Subtracting 0 from 20 leaves us with 20.
Since there are no more digits in the dividend, we add a zero to the remainder making it 200, and continue the process.

Advancing to step 8:
45 can be fit into 200 4 times, resulting in a remainder of 20.
Use 4 as the next digit of our solution. 
Result so far: 16679.04
The remainder is 20 after subtracting 180 from 200.
Since there are no more digits in the dividend, we add a zero to the remainder making it 200, and continue the process.

Moving on to step 9:
The number 45 fits into 200 4 times, leaving a remainder of 20.
Record the quotient 4 as the next digit in the result. 
Result so far: 16679.044
Subtract 180 from 200 to get 20.
Since there are no more digits in the dividend, we add a zero to the remainder making it 200, and continue the process.

The final result is 16679.044 with a remainder of 0.002.