We're dividing 13172069 by 90 
The aim is to understand the frequency of 90 in 13172069.

Let's proceed to step 1:
90 goes into 1 0 times with a remainder of 1.
Record the quotient 0 as the next digit in the result. 
Result so far: 0.0
If we subtract 0 from 1, we get 1.
Include the next digit (3) from the dividend after 1, then repeat: 13 / 90

Moving on to step 2:
13 divided by 90 is 0 with a remainder of 13.
Put 0 as the next digit of the answer. 
Result so far: 0.0
Deduct 0 from 13 and we're left with 13.
Include the next digit (1) from the dividend after 13, then repeat: 131 / 90

Going ahead to step 3:
When dividing 131 by 90, we get 1 with a remainder of 41.
The number 1 becomes the next digit in our result. 
Result so far: 1.0
Subtracting 90 from 131 leaves us with 41.
Include the next digit (7) from the dividend after 41, then repeat: 417 / 90

Going ahead to step 4:
When dividing 417 by 90, we get 4 with a remainder of 57.
Put 4 as the next digit of the answer. 
Result so far: 14.0
If we take 360 away from 417, we end up with 57.
Append the next digit (2) from the dividend to 57 and continue with: 572 / 90

On to step 5:
90 goes into 572 6 times with a remainder of 32.
Record the quotient 6 as the next digit in the result. 
Result so far: 146.0
If we subtract 540 from 572, we get 32.
Append the next digit (0) from the dividend to 32 and continue with: 320 / 90

On to step 6:
When dividing 320 by 90, we get 3 with a remainder of 50.
Write down 3 as next digit of the result. 
Result so far: 1463.0
Deduct 270 from 320 and we're left with 50.
Append the next digit (6) from the dividend to 50 and continue with: 506 / 90

Going ahead to step 7:
506 divided by 90 is 5 with a remainder of 56.
The next digit of our result is 5. 
Result so far: 14635.0
Deduct 450 from 506 and we're left with 56.
Append the next digit (9) from the dividend to 56 and continue with: 569 / 90

Let's proceed to step 8:
90 can be fit into 569 6 times, resulting in a remainder of 29.
The next digit of our result is 6. 
Result so far: 146356.0
If we subtract 540 from 569, we get 29.
Since there are no more digits in the dividend, we add a zero to the remainder making it 290, and continue the process.

Going ahead to step 9:
90 can be fit into 290 3 times, resulting in a remainder of 20.
Use 3 as the next digit of our solution. 
Result so far: 146356.3
The remainder is 20 after subtracting 270 from 290.
Since there are no more digits in the dividend, we add a zero to the remainder making it 200, and continue the process.

Step 10:
90 can be fit into 200 2 times, resulting in a remainder of 20.
Write down 2 as next digit of the result. 
Result so far: 146356.32
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.

Going ahead to step 11:
90 goes into 200 2 times with a remainder of 20.
The next digit of our result is 2. 
Result so far: 146356.322
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.

The final result is 146356.322 with a remainder of 0.002.