12897209 ÷ 90 
We're looking to find how many times 90 goes into 12897209.

Moving on to step 1:
If we divide 1 by 90, we get 0 and a remainder of 1.
The number 0 becomes the next digit in our result. 
Result so far: 0.0
Subtracting 0 from 1 leaves us with 1.
Include the next digit (2) from the dividend after 1, then repeat: 12 / 90

On to step 2:
The number 90 fits into 12 0 times, leaving a remainder of 12.
Write down 0 as next digit of the result. 
Result so far: 0.0
The remainder is 12 after subtracting 0 from 12.
Include the next digit (8) from the dividend after 12, then repeat: 128 / 90

Moving on to step 3:
If we divide 128 by 90, we get 1 and a remainder of 38.
Use 1 as the next digit of our solution. 
Result so far: 1.0
If we subtract 90 from 128, we get 38.
Bring next digit (9) of the dividend behind the 38 and repeat the process: 389 / 90

Moving on to step 4:
When dividing 389 by 90, we get 4 with a remainder of 29.
Use 4 as the next digit of our solution. 
Result so far: 14.0
The remainder is 29 after subtracting 360 from 389.
Append the next digit (7) from the dividend to 29 and continue with: 297 / 90

On to step 5:
The number 90 fits into 297 3 times, leaving a remainder of 27.
Use 3 as the next digit of our solution. 
Result so far: 143.0
Subtracting 270 from 297 leaves us with 27.
Grab the next digit (2) from the dividend, add it to 27, then carry on: 272 / 90

On to step 6:
When dividing 272 by 90, we get 3 with a remainder of 2.
Put 3 as the next digit of the answer. 
Result so far: 1433.0
Subtract 270 from 272 to get 2.
Fetch the next digit (0) from the dividend, attach it to 2 and continue: 20 / 90

Step 7:
When dividing 20 by 90, we get 0 with a remainder of 20.
Use 0 as the next digit of our solution. 
Result so far: 14330.0
The remainder is 20 after subtracting 0 from 20.
Take the next digit (9) from the dividend and append it to 20, then repeat: 209 / 90

Step 8:
The number 90 fits into 209 2 times, leaving a remainder of 29.
Use 2 as the next digit of our solution. 
Result so far: 143302.0
Deduct 180 from 209 and we're left with 29.
Since there are no more digits in the dividend, we add a zero to the remainder making it 290, and continue the process.

Let's proceed to step 9:
The number 90 fits into 290 3 times, leaving a remainder of 20.
The next digit of our result is 3. 
Result so far: 143302.3
The remainder is 20 after subtracting 270 from 290.
Since there are no more digits in the dividend, we add a zero to the remainder making it 200, and continue the process.

Step 10:
If we divide 200 by 90, we get 2 and a remainder of 20.
Record the quotient 2 as the next digit in the result. 
Result so far: 143302.32
If we take 180 away from 200, we end up with 20.
Since there are no more digits in the dividend, we add a zero to the remainder making it 200, and continue the process.

Moving on to step 11:
When dividing 200 by 90, we get 2 with a remainder of 20.
Put 2 as the next digit of the answer. 
Result so far: 143302.322
Subtracting 180 from 200 leaves us with 20.
Since there are no more digits in the dividend, we add a zero to the remainder making it 200, and continue the process.

In conclusion, the division gives 143302.322 with a balance of 0.002.