153399 divided by 45 
We want to figure out the number of times 153399 can be divided by 45.

Advancing to step 1:
If we divide 1 by 45, we get 0 and a remainder of 1.
Put 0 as the next digit of the answer. 
Result so far: 0.0
Deduct 0 from 1 and we're left with 1.
Include the next digit (5) from the dividend after 1, then repeat: 15 / 45

On to step 2:
If we divide 15 by 45, we get 0 and a remainder of 15.
Put 0 as the next digit of the answer. 
Result so far: 0.0
If we take 0 away from 15, we end up with 15.
Grab the next digit (3) from the dividend, add it to 15, then carry on: 153 / 45

On to step 3:
45 can be fit into 153 3 times, resulting in a remainder of 18.
The next digit of our result is 3. 
Result so far: 3.0
Deduct 135 from 153 and we're left with 18.
Grab the next digit (3) from the dividend, add it to 18, then carry on: 183 / 45

Step 4:
45 can be fit into 183 4 times, resulting in a remainder of 3.
The number 4 becomes the next digit in our result. 
Result so far: 34.0
If we subtract 180 from 183, we get 3.
Bring next digit (9) of the dividend behind the 3 and repeat the process: 39 / 45

On to step 5:
39 divided by 45 is 0 with a remainder of 39.
The next digit of our result is 0. 
Result so far: 340.0
Deduct 0 from 39 and we're left with 39.
Include the next digit (9) from the dividend after 39, then repeat: 399 / 45

Moving on to step 6:
The number 45 fits into 399 8 times, leaving a remainder of 39.
The next digit of our result is 8. 
Result so far: 3408.0
If we subtract 360 from 399, 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.

Going ahead to step 7:
45 can be fit into 390 8 times, resulting in a remainder of 30.
The next digit of our result is 8. 
Result so far: 3408.8
The remainder is 30 after subtracting 360 from 390.
Since there are no more digits in the dividend, we add a zero to the remainder making it 300, and continue the process.

On to step 8:
If we divide 300 by 45, we get 6 and a remainder of 30.
Use 6 as the next digit of our solution. 
Result so far: 3408.86
Subtract 270 from 300 to 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.

Advancing to step 9:
The number 45 fits into 300 6 times, leaving a remainder of 30.
The number 6 becomes the next digit in our result. 
Result so far: 3408.866
Subtract 270 from 300 to 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.

The final outcome is 3408.866, with a leftover of 0.003.