We're dividing 344209 by 90 
We want to figure out the number of times 344209 can be divided by 90.

On to step 1:
90 can be fit into 3 0 times, resulting in a remainder of 3.
Write down 0 as next digit of the result. 
Result so far: 0.0
Deduct 0 from 3 and we're left with 3.
Take the next digit (4) from the dividend and append it to 3, then repeat: 34 / 90

Moving on to step 2:
90 can be fit into 34 0 times, resulting in a remainder of 34.
Write down 0 as next digit of the result. 
Result so far: 0.0
If we subtract 0 from 34, we get 34.
Append the next digit (4) from the dividend to 34 and continue with: 344 / 90

Going ahead to step 3:
344 divided by 90 is 3 with a remainder of 74.
The next digit of our result is 3. 
Result so far: 3.0
If we subtract 270 from 344, we get 74.
Include the next digit (2) from the dividend after 74, then repeat: 742 / 90

On to step 4:
If we divide 742 by 90, we get 8 and a remainder of 22.
Put 8 as the next digit of the answer. 
Result so far: 38.0
Subtract 720 from 742 to get 22.
Include the next digit (0) from the dividend after 22, then repeat: 220 / 90

Moving on to step 5:
When dividing 220 by 90, we get 2 with a remainder of 40.
The number 2 becomes the next digit in our result. 
Result so far: 382.0
Subtract 180 from 220 to get 40.
Bring next digit (9) of the dividend behind the 40 and repeat the process: 409 / 90

Step 6:
The number 90 fits into 409 4 times, leaving a remainder of 49.
Write down 4 as next digit of the result. 
Result so far: 3824.0
If we take 360 away from 409, we end up with 49.
Since there are no more digits in the dividend, we add a zero to the remainder making it 490, and continue the process.

On to step 7:
490 divided by 90 is 5 with a remainder of 40.
Put 5 as the next digit of the answer. 
Result so far: 3824.5
Subtract 450 from 490 to get 40.
Since there are no more digits in the dividend, we add a zero to the remainder making it 400, and continue the process.

Step 8:
400 divided by 90 is 4 with a remainder of 40.
The next digit of our result is 4. 
Result so far: 3824.54
The remainder is 40 after subtracting 360 from 400.
Since there are no more digits in the dividend, we add a zero to the remainder making it 400, and continue the process.

Step 9:
The number 90 fits into 400 4 times, leaving a remainder of 40.
The next digit of our result is 4. 
Result so far: 3824.544
Subtract 360 from 400 to get 40.
Since there are no more digits in the dividend, we add a zero to the remainder making it 400, and continue the process.

The final outcome is 3824.544, with a leftover of 0.004.