We divide 708420 by 90
The aim is to understand the frequency of 90 in 708420.

Going ahead to step 1:
90 can be fit into 7 0 times, resulting in a remainder of 7.
The number 0 becomes the next digit in our result. 
Result so far: 0.0
Deduct 0 from 7 and we're left with 7.
Bring next digit (0) of the dividend behind the 7 and repeat the process: 70 / 90

Going ahead to step 2:
When dividing 70 by 90, we get 0 with a remainder of 70.
The next digit of our result is 0. 
Result so far: 0.0
Deduct 0 from 70 and we're left with 70.
Fetch the next digit (8) from the dividend, attach it to 70 and continue: 708 / 90

On to step 3:
708 divided by 90 is 7 with a remainder of 78.
Record the quotient 7 as the next digit in the result. 
Result so far: 7.0
Subtracting 630 from 708 leaves us with 78.
Bring next digit (4) of the dividend behind the 78 and repeat the process: 784 / 90

Let's proceed to step 4:
784 divided by 90 is 8 with a remainder of 64.
The next digit of our result is 8. 
Result so far: 78.0
If we subtract 720 from 784, we get 64.
Grab the next digit (2) from the dividend, add it to 64, then carry on: 642 / 90

On to step 5:
The number 90 fits into 642 7 times, leaving a remainder of 12.
The next digit of our result is 7. 
Result so far: 787.0
If we subtract 630 from 642, we get 12.
Append the next digit (0) from the dividend to 12 and continue with: 120 / 90

Going ahead to step 6:
If we divide 120 by 90, we get 1 and a remainder of 30.
The number 1 becomes the next digit in our result. 
Result so far: 7871.0
Subtract 90 from 120 to 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.

Step 7:
The number 90 fits into 300 3 times, leaving a remainder of 30.
Use 3 as the next digit of our solution. 
Result so far: 7871.3
Deduct 270 from 300 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.

On to step 8:
300 divided by 90 is 3 with a remainder of 30.
Record the quotient 3 as the next digit in the result. 
Result so far: 7871.33
Subtracting 270 from 300 leaves us 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.

The final result is 7871.33 with a remainder of 0.03.