We look at the division of 407482 by 90 
The aim is to understand the frequency of 90 in 407482.

Step 1:
90 can be fit into 4 0 times, resulting in a remainder of 4.
The next digit of our result is 0. 
Result so far: 0.0
The remainder is 4 after subtracting 0 from 4.
Append the next digit (0) from the dividend to 4 and continue with: 40 / 90

Step 2:
When dividing 40 by 90, we get 0 with a remainder of 40.
Record the quotient 0 as the next digit in the result. 
Result so far: 0.0
Subtract 0 from 40 to get 40.
Include the next digit (7) from the dividend after 40, then repeat: 407 / 90

Let's proceed to step 3:
90 goes into 407 4 times with a remainder of 47.
Use 4 as the next digit of our solution. 
Result so far: 4.0
Subtracting 360 from 407 leaves us with 47.
Append the next digit (4) from the dividend to 47 and continue with: 474 / 90

On to step 4:
474 divided by 90 is 5 with a remainder of 24.
The next digit of our result is 5. 
Result so far: 45.0
If we subtract 450 from 474, we get 24.
Include the next digit (8) from the dividend after 24, then repeat: 248 / 90

On to step 5:
The number 90 fits into 248 2 times, leaving a remainder of 68.
Write down 2 as next digit of the result. 
Result so far: 452.0
If we subtract 180 from 248, we get 68.
Bring next digit (2) of the dividend behind the 68 and repeat the process: 682 / 90

Moving on to step 6:
If we divide 682 by 90, we get 7 and a remainder of 52.
The next digit of our result is 7. 
Result so far: 4527.0
If we take 630 away from 682, we end up with 52.
Since there are no more digits in the dividend, we add a zero to the remainder making it 520, and continue the process.

Moving on to step 7:
520 divided by 90 is 5 with a remainder of 70.
Put 5 as the next digit of the answer. 
Result so far: 4527.5
If we take 450 away from 520, we end up with 70.
Since there are no more digits in the dividend, we add a zero to the remainder making it 700, and continue the process.

Moving on to step 8:
700 divided by 90 is 7 with a remainder of 70.
Write down 7 as next digit of the result. 
Result so far: 4527.57
Deduct 630 from 700 and we're left with 70.
Since there are no more digits in the dividend, we add a zero to the remainder making it 700, and continue the process.

Step 9:
If we divide 700 by 90, we get 7 and a remainder of 70.
Record the quotient 7 as the next digit in the result. 
Result so far: 4527.577
Subtract 630 from 700 to get 70.
Since there are no more digits in the dividend, we add a zero to the remainder making it 700, and continue the process.

After the division, we end up with 4527.577 and a remainder of 0.007.