We look at the division of 542809 by 45 
The aim is to understand the frequency of 45 in 542809.

On to step 1:
45 goes into 5 0 times with a remainder of 5.
Write down 0 as next digit of the result. 
Result so far: 0.0
Subtracting 0 from 5 leaves us with 5.
Grab the next digit (4) from the dividend, add it to 5, then carry on: 54 / 45

Going ahead to step 2:
54 divided by 45 is 1 with a remainder of 9.
Put 1 as the next digit of the answer. 
Result so far: 1.0
If we subtract 45 from 54, we get 9.
Take the next digit (2) from the dividend and append it to 9, then repeat: 92 / 45

Moving on to step 3:
When dividing 92 by 45, we get 2 with a remainder of 2.
Put 2 as the next digit of the answer. 
Result so far: 12.0
If we take 90 away from 92, we end up with 2.
Append the next digit (8) from the dividend to 2 and continue with: 28 / 45

On to step 4:
The number 45 fits into 28 0 times, leaving a remainder of 28.
Use 0 as the next digit of our solution. 
Result so far: 120.0
Subtracting 0 from 28 leaves us with 28.
Include the next digit (0) from the dividend after 28, then repeat: 280 / 45

Advancing to step 5:
If we divide 280 by 45, we get 6 and a remainder of 10.
Write down 6 as next digit of the result. 
Result so far: 1206.0
If we take 270 away from 280, we end up with 10.
Bring next digit (9) of the dividend behind the 10 and repeat the process: 109 / 45

Going ahead to step 6:
If we divide 109 by 45, we get 2 and a remainder of 19.
Use 2 as the next digit of our solution. 
Result so far: 12062.0
Deduct 90 from 109 and we're left with 19.
Since there are no more digits in the dividend, we add a zero to the remainder making it 190, and continue the process.

Going ahead to step 7:
If we divide 190 by 45, we get 4 and a remainder of 10.
Put 4 as the next digit of the answer. 
Result so far: 12062.4
The remainder is 10 after subtracting 180 from 190.
Since there are no more digits in the dividend, we add a zero to the remainder making it 100, and continue the process.

Going ahead to step 8:
100 divided by 45 is 2 with a remainder of 10.
Write down 2 as next digit of the result. 
Result so far: 12062.42
The remainder is 10 after subtracting 90 from 100.
Since there are no more digits in the dividend, we add a zero to the remainder making it 100, and continue the process.

On to step 9:
The number 45 fits into 100 2 times, leaving a remainder of 10.
Use 2 as the next digit of our solution. 
Result so far: 12062.422
Deduct 90 from 100 and we're left with 10.
Since there are no more digits in the dividend, we add a zero to the remainder making it 100, and continue the process.

Our division results in 12062.422 with a remaining 0.001.