Let's divide 28153431 by 90
The aim is to understand the frequency of 90 in 28153431.

On to step 1:
When dividing 2 by 90, we get 0 with a remainder of 2.
Use 0 as the next digit of our solution. 
Result so far: 0.0
Deduct 0 from 2 and we're left with 2.
Take the next digit (8) from the dividend and append it to 2, then repeat: 28 / 90

Step 2:
90 goes into 28 0 times with a remainder of 28.
Use 0 as the next digit of our solution. 
Result so far: 0.0
If we subtract 0 from 28, we get 28.
Take the next digit (1) from the dividend and append it to 28, then repeat: 281 / 90

Let's proceed to step 3:
The number 90 fits into 281 3 times, leaving a remainder of 11.
Put 3 as the next digit of the answer. 
Result so far: 3.0
If we take 270 away from 281, we end up with 11.
Grab the next digit (5) from the dividend, add it to 11, then carry on: 115 / 90

Let's proceed to step 4:
115 divided by 90 is 1 with a remainder of 25.
The next digit of our result is 1. 
Result so far: 31.0
Subtracting 90 from 115 leaves us with 25.
Grab the next digit (3) from the dividend, add it to 25, then carry on: 253 / 90

On to step 5:
90 can be fit into 253 2 times, resulting in a remainder of 73.
The next digit of our result is 2. 
Result so far: 312.0
The remainder is 73 after subtracting 180 from 253.
Grab the next digit (4) from the dividend, add it to 73, then carry on: 734 / 90

Moving on to step 6:
90 can be fit into 734 8 times, resulting in a remainder of 14.
The number 8 becomes the next digit in our result. 
Result so far: 3128.0
Subtract 720 from 734 to get 14.
Bring next digit (3) of the dividend behind the 14 and repeat the process: 143 / 90

Let's proceed to step 7:
When dividing 143 by 90, we get 1 with a remainder of 53.
The next digit of our result is 1. 
Result so far: 31281.0
Subtracting 90 from 143 leaves us with 53.
Append the next digit (1) from the dividend to 53 and continue with: 531 / 90

Let's proceed to step 8:
531 divided by 90 is 5 with a remainder of 81.
The number 5 becomes the next digit in our result. 
Result so far: 312815.0
If we subtract 450 from 531, we get 81.
Since there are no more digits in the dividend, we add a zero to the remainder making it 810, and continue the process.

Step 9:
The number 90 fits into 810 9 times, leaving a remainder of 0.
The number 9 becomes the next digit in our result. 
Result so far: 312815.9
Deduct 810 from 810 and we're left with 0.
Since there are no more digits in the dividend, we add a zero to the remainder making it 0, and continue the process.

On to step 10:
90 goes into 0 0 times with a remainder of 0.
The number 0 becomes the next digit in our result. 
Result so far: 312815.9
Subtract 0 from 0 to get 0.
Since there are no more digits in the dividend, we add a zero to the remainder making it 0, and continue the process.

Let's proceed to step 11:
90 goes into 0 0 times with a remainder of 0.
The number 0 becomes the next digit in our result. 
Result so far: 312815.9
Deduct 0 from 0 and we're left with 0.
Since there are no more digits in the dividend, we add a zero to the remainder making it 0, and continue the process.

Our division results in 312815.9 with a remaining 0.0.