We're dividing 35438947 by 90 
The aim is to understand the frequency of 90 in 35438947.

Step 1:
3 divided by 90 is 0 with a remainder of 3.
The number 0 becomes the next digit in our result. 
Result so far: 0.0
Subtract 0 from 3 to get 3.
Fetch the next digit (5) from the dividend, attach it to 3 and continue: 35 / 90

Moving on to step 2:
When dividing 35 by 90, we get 0 with a remainder of 35.
Put 0 as the next digit of the answer. 
Result so far: 0.0
The remainder is 35 after subtracting 0 from 35.
Fetch the next digit (4) from the dividend, attach it to 35 and continue: 354 / 90

Advancing to step 3:
90 can be fit into 354 3 times, resulting in a remainder of 84.
Write down 3 as next digit of the result. 
Result so far: 3.0
The remainder is 84 after subtracting 270 from 354.
Take the next digit (3) from the dividend and append it to 84, then repeat: 843 / 90

Let's proceed to step 4:
The number 90 fits into 843 9 times, leaving a remainder of 33.
The next digit of our result is 9. 
Result so far: 39.0
Subtracting 810 from 843 leaves us with 33.
Take the next digit (8) from the dividend and append it to 33, then repeat: 338 / 90

Moving on to step 5:
90 can be fit into 338 3 times, resulting in a remainder of 68.
Write down 3 as next digit of the result. 
Result so far: 393.0
Deduct 270 from 338 and we're left with 68.
Fetch the next digit (9) from the dividend, attach it to 68 and continue: 689 / 90

Step 6:
If we divide 689 by 90, we get 7 and a remainder of 59.
The number 7 becomes the next digit in our result. 
Result so far: 3937.0
Subtracting 630 from 689 leaves us with 59.
Bring next digit (4) of the dividend behind the 59 and repeat the process: 594 / 90

Step 7:
If we divide 594 by 90, we get 6 and a remainder of 54.
Use 6 as the next digit of our solution. 
Result so far: 39376.0
If we take 540 away from 594, we end up with 54.
Append the next digit (7) from the dividend to 54 and continue with: 547 / 90

On to step 8:
If we divide 547 by 90, we get 6 and a remainder of 7.
Use 6 as the next digit of our solution. 
Result so far: 393766.0
Deduct 540 from 547 and we're left with 7.
Since there are no more digits in the dividend, we add a zero to the remainder making it 70, and continue the process.

Let's proceed to step 9:
90 goes into 70 0 times with a remainder of 70.
Record the quotient 0 as the next digit in the result. 
Result so far: 393766.0
Subtract 0 from 70 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.

Step 10:
90 can be fit into 700 7 times, resulting in a remainder of 70.
Record the quotient 7 as the next digit in the result. 
Result so far: 393766.07
The remainder is 70 after subtracting 630 from 700.
Since there are no more digits in the dividend, we add a zero to the remainder making it 700, and continue the process.

On to step 11:
700 divided by 90 is 7 with a remainder of 70.
Record the quotient 7 as the next digit in the result. 
Result so far: 393766.077
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.

The final outcome is 393766.077, with a leftover of 0.007.