We look at the division of 642455 by 45 
The aim is to understand the frequency of 45 in 642455.

Let's proceed to step 1:
45 goes into 6 0 times with a remainder of 6.
Put 0 as the next digit of the answer. 
Result so far: 0.0
If we subtract 0 from 6, we get 6.
Append the next digit (4) from the dividend to 6 and continue with: 64 / 45

On to step 2:
45 goes into 64 1 times with a remainder of 19.
Put 1 as the next digit of the answer. 
Result so far: 1.0
If we subtract 45 from 64, we get 19.
Fetch the next digit (2) from the dividend, attach it to 19 and continue: 192 / 45

Going ahead to step 3:
When dividing 192 by 45, we get 4 with a remainder of 12.
The next digit of our result is 4. 
Result so far: 14.0
If we take 180 away from 192, we end up with 12.
Grab the next digit (4) from the dividend, add it to 12, then carry on: 124 / 45

Step 4:
45 can be fit into 124 2 times, resulting in a remainder of 34.
Record the quotient 2 as the next digit in the result. 
Result so far: 142.0
The remainder is 34 after subtracting 90 from 124.
Fetch the next digit (5) from the dividend, attach it to 34 and continue: 345 / 45

On to step 5:
45 goes into 345 7 times with a remainder of 30.
Write down 7 as next digit of the result. 
Result so far: 1427.0
Deduct 315 from 345 and we're left with 30.
Fetch the next digit (5) from the dividend, attach it to 30 and continue: 305 / 45

Step 6:
If we divide 305 by 45, we get 6 and a remainder of 35.
The number 6 becomes the next digit in our result. 
Result so far: 14276.0
Subtracting 270 from 305 leaves us 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.

On to step 7:
When dividing 350 by 45, we get 7 with a remainder of 35.
The number 7 becomes the next digit in our result. 
Result so far: 14276.7
Subtracting 315 from 350 leaves us 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.

Moving on to step 8:
45 can be fit into 350 7 times, resulting in a remainder of 35.
Put 7 as the next digit of the answer. 
Result so far: 14276.77
Deduct 315 from 350 and we're left 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 14276.77 and a remainder of 0.035.