We look at the division of 261021 by 90 
Let's see how many times 90 fits into 261021.

On to step 1:
When dividing 2 by 90, we get 0 with a remainder of 2.
Use 0 as the next digit of our solution. 
Result so far: 0.0
Subtracting 0 from 2 leaves us with 2.
Take the next digit (6) from the dividend and append it to 2, then repeat: 26 / 90

Let's proceed to step 2:
90 can be fit into 26 0 times, resulting in a remainder of 26.
Record the quotient 0 as the next digit in the result. 
Result so far: 0.0
Subtract 0 from 26 to get 26.
Fetch the next digit (1) from the dividend, attach it to 26 and continue: 261 / 90

Moving on to step 3:
261 divided by 90 is 2 with a remainder of 81.
Put 2 as the next digit of the answer. 
Result so far: 2.0
Subtracting 180 from 261 leaves us with 81.
Include the next digit (0) from the dividend after 81, then repeat: 810 / 90

Moving on to step 4:
If we divide 810 by 90, we get 9 and a remainder of 0.
Use 9 as the next digit of our solution. 
Result so far: 29.0
Deduct 810 from 810 and we're left with 0.
Bring next digit (2) of the dividend behind the 0 and repeat the process: 2 / 90

On to step 5:
The number 90 fits into 2 0 times, leaving a remainder of 2.
Put 0 as the next digit of the answer. 
Result so far: 290.0
The remainder is 2 after subtracting 0 from 2.
Append the next digit (1) from the dividend to 2 and continue with: 21 / 90

Moving on to step 6:
21 divided by 90 is 0 with a remainder of 21.
Put 0 as the next digit of the answer. 
Result so far: 2900.0
If we subtract 0 from 21, we get 21.
Since there are no more digits in the dividend, we add a zero to the remainder making it 210, and continue the process.

Step 7:
90 goes into 210 2 times with a remainder of 30.
The number 2 becomes the next digit in our result. 
Result so far: 2900.2
Deduct 180 from 210 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.

Moving on to step 8:
When dividing 300 by 90, we get 3 with a remainder of 30.
The number 3 becomes the next digit in our result. 
Result so far: 2900.23
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.

Going ahead to step 9:
When dividing 300 by 90, we get 3 with a remainder of 30.
Use 3 as the next digit of our solution. 
Result so far: 2900.233
If we subtract 270 from 300, we 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.

The final outcome is 2900.233, with a leftover of 0.003.