78772569 divided by 90 
The aim is to understand the frequency of 90 in 78772569.

Going ahead to step 1:
The number 90 fits into 7 0 times, leaving a remainder of 7.
Use 0 as the next digit of our solution. 
Result so far: 0.0
Subtract 0 from 7 to get 7.
Include the next digit (8) from the dividend after 7, then repeat: 78 / 90

Moving on to step 2:
90 can be fit into 78 0 times, resulting in a remainder of 78.
Use 0 as the next digit of our solution. 
Result so far: 0.0
Deduct 0 from 78 and we're left with 78.
Fetch the next digit (7) from the dividend, attach it to 78 and continue: 787 / 90

Advancing to step 3:
When dividing 787 by 90, we get 8 with a remainder of 67.
The number 8 becomes the next digit in our result. 
Result so far: 8.0
Subtract 720 from 787 to get 67.
Take the next digit (7) from the dividend and append it to 67, then repeat: 677 / 90

On to step 4:
90 can be fit into 677 7 times, resulting in a remainder of 47.
The number 7 becomes the next digit in our result. 
Result so far: 87.0
Subtracting 630 from 677 leaves us with 47.
Fetch the next digit (2) from the dividend, attach it to 47 and continue: 472 / 90

Step 5:
90 goes into 472 5 times with a remainder of 22.
The number 5 becomes the next digit in our result. 
Result so far: 875.0
Subtracting 450 from 472 leaves us with 22.
Bring next digit (5) of the dividend behind the 22 and repeat the process: 225 / 90

On to step 6:
90 goes into 225 2 times with a remainder of 45.
The next digit of our result is 2. 
Result so far: 8752.0
Deduct 180 from 225 and we're left with 45.
Grab the next digit (6) from the dividend, add it to 45, then carry on: 456 / 90

Advancing to step 7:
When dividing 456 by 90, we get 5 with a remainder of 6.
The next digit of our result is 5. 
Result so far: 87525.0
Deduct 450 from 456 and we're left with 6.
Fetch the next digit (9) from the dividend, attach it to 6 and continue: 69 / 90

Going ahead to step 8:
The number 90 fits into 69 0 times, leaving a remainder of 69.
Write down 0 as next digit of the result. 
Result so far: 875250.0
Subtracting 0 from 69 leaves us with 69.
Since there are no more digits in the dividend, we add a zero to the remainder making it 690, and continue the process.

Step 9:
690 divided by 90 is 7 with a remainder of 60.
Record the quotient 7 as the next digit in the result. 
Result so far: 875250.7
Deduct 630 from 690 and we're left with 60.
Since there are no more digits in the dividend, we add a zero to the remainder making it 600, and continue the process.

Going ahead to step 10:
If we divide 600 by 90, we get 6 and a remainder of 60.
The next digit of our result is 6. 
Result so far: 875250.76
Subtract 540 from 600 to get 60.
Since there are no more digits in the dividend, we add a zero to the remainder making it 600, and continue the process.

Let's proceed to step 11:
If we divide 600 by 90, we get 6 and a remainder of 60.
The next digit of our result is 6. 
Result so far: 875250.766
If we subtract 540 from 600, we get 60.
Since there are no more digits in the dividend, we add a zero to the remainder making it 600, and continue the process.

The quotient of the division is 875250.766, and the remainder is 0.006.