We look at the division of 331257 by 90 
The aim is to understand the frequency of 90 in 331257.

Moving on to step 1:
If we divide 3 by 90, we get 0 and a remainder of 3.
Record the quotient 0 as the next digit in the result. 
Result so far: 0.0
If we subtract 0 from 3, we get 3.
Grab the next digit (3) from the dividend, add it to 3, then carry on: 33 / 90

Going ahead to step 2:
33 divided by 90 is 0 with a remainder of 33.
The next digit of our result is 0. 
Result so far: 0.0
The remainder is 33 after subtracting 0 from 33.
Bring next digit (1) of the dividend behind the 33 and repeat the process: 331 / 90

Let's proceed to step 3:
331 divided by 90 is 3 with a remainder of 61.
Write down 3 as next digit of the result. 
Result so far: 3.0
If we subtract 270 from 331, we get 61.
Take the next digit (2) from the dividend and append it to 61, then repeat: 612 / 90

Going ahead to step 4:
When dividing 612 by 90, we get 6 with a remainder of 72.
Write down 6 as next digit of the result. 
Result so far: 36.0
The remainder is 72 after subtracting 540 from 612.
Grab the next digit (5) from the dividend, add it to 72, then carry on: 725 / 90

Going ahead to step 5:
If we divide 725 by 90, we get 8 and a remainder of 5.
Use 8 as the next digit of our solution. 
Result so far: 368.0
If we take 720 away from 725, we end up with 5.
Fetch the next digit (7) from the dividend, attach it to 5 and continue: 57 / 90

On to step 6:
The number 90 fits into 57 0 times, leaving a remainder of 57.
Write down 0 as next digit of the result. 
Result so far: 3680.0
Deduct 0 from 57 and we're left with 57.
Since there are no more digits in the dividend, we add a zero to the remainder making it 570, and continue the process.

On to step 7:
The number 90 fits into 570 6 times, leaving a remainder of 30.
Write down 6 as next digit of the result. 
Result so far: 3680.6
Deduct 540 from 570 and we're left with 30.
Since there are no more digits in the dividend, we add a zero to the remainder making it 300, and continue the process.

Moving on to step 8:
90 goes into 300 3 times with a remainder of 30.
Use 3 as the next digit of our solution. 
Result so far: 3680.63
If we subtract 270 from 300, we get 30.
Since there are no more digits in the dividend, we add a zero to the remainder making it 300, and continue the process.

On to step 9:
When dividing 300 by 90, we get 3 with a remainder of 30.
The next digit of our result is 3. 
Result so far: 3680.633
If we subtract 270 from 300, we get 30.
Since there are no more digits in the dividend, we add a zero to the remainder making it 300, and continue the process.

The quotient of the division is 3680.633, and the remainder is 0.003.