We divide 666690 by 90
Our goal is to divide 666690 by 90.

Moving on to step 1:
When dividing 6 by 90, we get 0 with a remainder of 6.
The number 0 becomes the next digit in our result. 
Result so far: 0.0
Deduct 0 from 6 and we're left with 6.
Append the next digit (6) from the dividend to 6 and continue with: 66 / 90

Going ahead to step 2:
The number 90 fits into 66 0 times, leaving a remainder of 66.
Record the quotient 0 as the next digit in the result. 
Result so far: 0.0
Deduct 0 from 66 and we're left with 66.
Bring next digit (6) of the dividend behind the 66 and repeat the process: 666 / 90

Step 3:
666 divided by 90 is 7 with a remainder of 36.
Use 7 as the next digit of our solution. 
Result so far: 7.0
Deduct 630 from 666 and we're left with 36.
Append the next digit (6) from the dividend to 36 and continue with: 366 / 90

Going ahead to step 4:
When dividing 366 by 90, we get 4 with a remainder of 6.
Put 4 as the next digit of the answer. 
Result so far: 74.0
The remainder is 6 after subtracting 360 from 366.
Append the next digit (9) from the dividend to 6 and continue with: 69 / 90

Let's proceed to step 5:
If we divide 69 by 90, we get 0 and a remainder of 69.
Record the quotient 0 as the next digit in the result. 
Result so far: 740.0
Deduct 0 from 69 and we're left with 69.
Fetch the next digit (0) from the dividend, attach it to 69 and continue: 690 / 90

Let's proceed to step 6:
The number 90 fits into 690 7 times, leaving a remainder of 60.
Put 7 as the next digit of the answer. 
Result so far: 7407.0
If we subtract 630 from 690, 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.

On to step 7:
When dividing 600 by 90, we get 6 with a remainder of 60.
The next digit of our result is 6. 
Result so far: 7407.6
The remainder is 60 after subtracting 540 from 600.
Since there are no more digits in the dividend, we add a zero to the remainder making it 600, and continue the process.

Advancing to step 8:
90 can be fit into 600 6 times, resulting in a remainder of 60.
Use 6 as the next digit of our solution. 
Result so far: 7407.66
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 final outcome is 7407.66, with a leftover of 0.06.