We look at the division of 81491407 by 52 
The aim is to understand the frequency of 52 in 81491407.

Step 1:
If we divide 8 by 52, we get 0 and a remainder of 8.
Put 0 as the next digit of the answer. 
Result so far: 0.0
Subtract 0 from 8 to get 8.
Bring next digit (1) of the dividend behind the 8 and repeat the process: 81 / 52

On to step 2:
52 goes into 81 1 times with a remainder of 29.
The number 1 becomes the next digit in our result. 
Result so far: 1.0
If we subtract 52 from 81, we get 29.
Take the next digit (4) from the dividend and append it to 29, then repeat: 294 / 52

Moving on to step 3:
294 divided by 52 is 5 with a remainder of 34.
Use 5 as the next digit of our solution. 
Result so far: 15.0
If we take 260 away from 294, we end up with 34.
Take the next digit (9) from the dividend and append it to 34, then repeat: 349 / 52

On to step 4:
52 goes into 349 6 times with a remainder of 37.
Put 6 as the next digit of the answer. 
Result so far: 156.0
If we take 312 away from 349, we end up with 37.
Fetch the next digit (1) from the dividend, attach it to 37 and continue: 371 / 52

Going ahead to step 5:
371 divided by 52 is 7 with a remainder of 7.
Use 7 as the next digit of our solution. 
Result so far: 1567.0
Subtracting 364 from 371 leaves us with 7.
Grab the next digit (4) from the dividend, add it to 7, then carry on: 74 / 52

On to step 6:
52 goes into 74 1 times with a remainder of 22.
Use 1 as the next digit of our solution. 
Result so far: 15671.0
If we subtract 52 from 74, we get 22.
Take the next digit (0) from the dividend and append it to 22, then repeat: 220 / 52

Going ahead to step 7:
52 goes into 220 4 times with a remainder of 12.
Write down 4 as next digit of the result. 
Result so far: 156714.0
If we take 208 away from 220, we end up with 12.
Grab the next digit (7) from the dividend, add it to 12, then carry on: 127 / 52

On to step 8:
127 divided by 52 is 2 with a remainder of 23.
Use 2 as the next digit of our solution. 
Result so far: 1567142.0
Subtracting 104 from 127 leaves us with 23.
Since there are no more digits in the dividend, we add a zero to the remainder making it 230, and continue the process.

Let's proceed to step 9:
The number 52 fits into 230 4 times, leaving a remainder of 22.
The next digit of our result is 4. 
Result so far: 1567142.4
If we subtract 208 from 230, we get 22.
Since there are no more digits in the dividend, we add a zero to the remainder making it 220, and continue the process.

Let's proceed to step 10:
52 can be fit into 220 4 times, resulting in a remainder of 12.
Use 4 as the next digit of our solution. 
Result so far: 1567142.44
Subtracting 208 from 220 leaves us with 12.
Since there are no more digits in the dividend, we add a zero to the remainder making it 120, and continue the process.

The final outcome is 1567142.44, with a leftover of 0.012.