We look at the division of 312408 by 90 
Our goal is to divide 312408 by 90.

Advancing to step 1:
When dividing 3 by 90, we get 0 with a remainder of 3.
Write down 0 as next digit of the result. 
Result so far: 0.0
Subtracting 0 from 3 leaves us with 3.
Include the next digit (1) from the dividend after 3, then repeat: 31 / 90

Step 2:
The number 90 fits into 31 0 times, leaving a remainder of 31.
Write down 0 as next digit of the result. 
Result so far: 0.0
The remainder is 31 after subtracting 0 from 31.
Include the next digit (2) from the dividend after 31, then repeat: 312 / 90

On to step 3:
90 can be fit into 312 3 times, resulting in a remainder of 42.
The number 3 becomes the next digit in our result. 
Result so far: 3.0
If we subtract 270 from 312, we get 42.
Grab the next digit (4) from the dividend, add it to 42, then carry on: 424 / 90

Let's proceed to step 4:
If we divide 424 by 90, we get 4 and a remainder of 64.
The next digit of our result is 4. 
Result so far: 34.0
The remainder is 64 after subtracting 360 from 424.
Fetch the next digit (0) from the dividend, attach it to 64 and continue: 640 / 90

On to step 5:
90 goes into 640 7 times with a remainder of 10.
Use 7 as the next digit of our solution. 
Result so far: 347.0
Subtracting 630 from 640 leaves us with 10.
Include the next digit (8) from the dividend after 10, then repeat: 108 / 90

Going ahead to step 6:
90 goes into 108 1 times with a remainder of 18.
Use 1 as the next digit of our solution. 
Result so far: 3471.0
If we subtract 90 from 108, we get 18.
Since there are no more digits in the dividend, we add a zero to the remainder making it 180, and continue the process.

Advancing to step 7:
If we divide 180 by 90, we get 2 and a remainder of 0.
Put 2 as the next digit of the answer. 
Result so far: 3471.2
Subtract 180 from 180 to get 0.
Since there are no more digits in the dividend, we add a zero to the remainder making it 0, and continue the process.

Going ahead to step 8:
90 goes into 0 0 times with a remainder of 0.
Use 0 as the next digit of our solution. 
Result so far: 3471.2
Subtracting 0 from 0 leaves us with 0.
Since there are no more digits in the dividend, we add a zero to the remainder making it 0, and continue the process.

Let's proceed to step 9:
When dividing 0 by 90, we get 0 with a remainder of 0.
Record the quotient 0 as the next digit in the result. 
Result so far: 3471.2
If we take 0 away from 0, we end up with 0.
Since there are no more digits in the dividend, we add a zero to the remainder making it 0, and continue the process.

The final result is 3471.2 with a remainder of 0.0.