623904 ÷ 45 
We're looking to find how many times 45 goes into 623904.

Going ahead to step 1:
45 can be fit into 6 0 times, resulting in a remainder of 6.
Use 0 as the next digit of our solution. 
Result so far: 0.0
Subtract 0 from 6 to get 6.
Fetch the next digit (2) from the dividend, attach it to 6 and continue: 62 / 45

Advancing to step 2:
The number 45 fits into 62 1 times, leaving a remainder of 17.
Put 1 as the next digit of the answer. 
Result so far: 1.0
If we take 45 away from 62, we end up with 17.
Include the next digit (3) from the dividend after 17, then repeat: 173 / 45

Advancing to step 3:
The number 45 fits into 173 3 times, leaving a remainder of 38.
Use 3 as the next digit of our solution. 
Result so far: 13.0
If we take 135 away from 173, we end up with 38.
Grab the next digit (9) from the dividend, add it to 38, then carry on: 389 / 45

Step 4:
389 divided by 45 is 8 with a remainder of 29.
The number 8 becomes the next digit in our result. 
Result so far: 138.0
Subtract 360 from 389 to get 29.
Append the next digit (0) from the dividend to 29 and continue with: 290 / 45

On to step 5:
45 goes into 290 6 times with a remainder of 20.
Write down 6 as next digit of the result. 
Result so far: 1386.0
If we subtract 270 from 290, we get 20.
Fetch the next digit (4) from the dividend, attach it to 20 and continue: 204 / 45

Advancing to step 6:
45 can be fit into 204 4 times, resulting in a remainder of 24.
The next digit of our result is 4. 
Result so far: 13864.0
If we subtract 180 from 204, we get 24.
Since there are no more digits in the dividend, we add a zero to the remainder making it 240, and continue the process.

Going ahead to step 7:
When dividing 240 by 45, we get 5 with a remainder of 15.
The next digit of our result is 5. 
Result so far: 13864.5
Subtracting 225 from 240 leaves us with 15.
Since there are no more digits in the dividend, we add a zero to the remainder making it 150, and continue the process.

Going ahead to step 8:
150 divided by 45 is 3 with a remainder of 15.
Put 3 as the next digit of the answer. 
Result so far: 13864.53
If we take 135 away from 150, we end up with 15.
Since there are no more digits in the dividend, we add a zero to the remainder making it 150, and continue the process.

Let's proceed to step 9:
45 goes into 150 3 times with a remainder of 15.
Use 3 as the next digit of our solution. 
Result so far: 13864.533
If we take 135 away from 150, we end up with 15.
Since there are no more digits in the dividend, we add a zero to the remainder making it 150, and continue the process.

The final outcome is 13864.533, with a leftover of 0.0015.