Let's divide 45399 by 42
We're looking to find how many times 42 goes into 45399.

Advancing to step 1:
42 goes into 4 0 times with a remainder of 4.
The number 0 becomes the next digit in our result. 
Result so far: 0.0
Subtract 0 from 4 to get 4.
Fetch the next digit (5) from the dividend, attach it to 4 and continue: 45 / 42

Step 2:
45 divided by 42 is 1 with a remainder of 3.
The next digit of our result is 1. 
Result so far: 1.0
If we take 42 away from 45, we end up with 3.
Grab the next digit (3) from the dividend, add it to 3, then carry on: 33 / 42

Moving on to step 3:
The number 42 fits into 33 0 times, leaving a remainder of 33.
The number 0 becomes the next digit in our result. 
Result so far: 10.0
Subtracting 0 from 33 leaves us with 33.
Append the next digit (9) from the dividend to 33 and continue with: 339 / 42

Moving on to step 4:
42 can be fit into 339 8 times, resulting in a remainder of 3.
Use 8 as the next digit of our solution. 
Result so far: 108.0
Deduct 336 from 339 and we're left with 3.
Grab the next digit (9) from the dividend, add it to 3, then carry on: 39 / 42

On to step 5:
39 divided by 42 is 0 with a remainder of 39.
Put 0 as the next digit of the answer. 
Result so far: 1080.0
If we subtract 0 from 39, we get 39.
Since there are no more digits in the dividend, we add a zero to the remainder making it 390, and continue the process.

Step 6:
42 can be fit into 390 9 times, resulting in a remainder of 12.
The number 9 becomes the next digit in our result. 
Result so far: 1080.9
Subtract 378 from 390 to get 12.
Since there are no more digits in the dividend, we add a zero to the remainder making it 120, and continue the process.

On to step 7:
When dividing 120 by 42, we get 2 with a remainder of 36.
Use 2 as the next digit of our solution. 
Result so far: 1080.92
If we subtract 84 from 120, we get 36.
Since there are no more digits in the dividend, we add a zero to the remainder making it 360, and continue the process.

Let's proceed to step 8:
If we divide 360 by 42, we get 8 and a remainder of 24.
Record the quotient 8 as the next digit in the result. 
Result so far: 1080.928
Subtract 336 from 360 to 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.

Let's proceed to step 9:
If we divide 240 by 42, we get 5 and a remainder of 30.
Use 5 as the next digit of our solution. 
Result so far: 1080.9285
If we subtract 210 from 240, 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.

Step 10:
300 divided by 42 is 7 with a remainder of 6.
The next digit of our result is 7. 
Result so far: 1080.92857
If we take 294 away from 300, we end up with 6.
Since there are no more digits in the dividend, we add a zero to the remainder making it 60, and continue the process.

Advancing to step 11:
42 goes into 60 1 times with a remainder of 18.
Put 1 as the next digit of the answer. 
Result so far: 1080.928571
Subtract 42 from 60 to 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.

Step 12:
180 divided by 42 is 4 with a remainder of 12.
Record the quotient 4 as the next digit in the result. 
Result so far: 1080.9285714
If we take 168 away from 180, we end up with 12.
Since there are no more digits in the dividend, we add a zero to the remainder making it 120, and continue the process.

Advancing to step 13:
42 goes into 120 2 times with a remainder of 36.
Record the quotient 2 as the next digit in the result. 
Result so far: 1080.92857142
The remainder is 36 after subtracting 84 from 120.
Since there are no more digits in the dividend, we add a zero to the remainder making it 360, and continue the process.

The final result is 1080.92857142 with a remainder of 3.6e-08.