We look at the division of 648790 by 90 
We want to figure out the number of times 648790 can be divided by 90.

Step 1:
90 can be fit into 6 0 times, resulting in a remainder of 6.
Put 0 as the next digit of the answer. 
Result so far: 0.0
Deduct 0 from 6 and we're left with 6.
Take the next digit (4) from the dividend and append it to 6, then repeat: 64 / 90

Step 2:
90 goes into 64 0 times with a remainder of 64.
The number 0 becomes the next digit in our result. 
Result so far: 0.0
If we take 0 away from 64, we end up with 64.
Append the next digit (8) from the dividend to 64 and continue with: 648 / 90

Let's proceed to step 3:
90 can be fit into 648 7 times, resulting in a remainder of 18.
Write down 7 as next digit of the result. 
Result so far: 7.0
If we take 630 away from 648, we end up with 18.
Grab the next digit (7) from the dividend, add it to 18, then carry on: 187 / 90

Moving on to step 4:
The number 90 fits into 187 2 times, leaving a remainder of 7.
Record the quotient 2 as the next digit in the result. 
Result so far: 72.0
Deduct 180 from 187 and we're left with 7.
Take the next digit (9) from the dividend and append it to 7, then repeat: 79 / 90

Moving on to step 5:
When dividing 79 by 90, we get 0 with a remainder of 79.
Write down 0 as next digit of the result. 
Result so far: 720.0
The remainder is 79 after subtracting 0 from 79.
Grab the next digit (0) from the dividend, add it to 79, then carry on: 790 / 90

On to step 6:
90 goes into 790 8 times with a remainder of 70.
Put 8 as the next digit of the answer. 
Result so far: 7208.0
Subtracting 720 from 790 leaves us 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 7:
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: 7208.7
If we take 630 away from 700, 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.

On to step 8:
The number 90 fits into 700 7 times, leaving a remainder of 70.
The number 7 becomes the next digit in our result. 
Result so far: 7208.77
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.

The final outcome is 7208.77, with a leftover of 0.07.