We're dividing 1239998 by 855 
We want to figure out the number of times 1239998 can be divided by 855.

Step 1:
855 can be fit into 1 0 times, resulting in a remainder of 1.
The number 0 becomes the next digit in our result. 
Result so far: 0.0
Deduct 0 from 1 and we're left with 1.
Bring next digit (2) of the dividend behind the 1 and repeat the process: 12 / 855

Going ahead to step 2:
12 divided by 855 is 0 with a remainder of 12.
Record the quotient 0 as the next digit in the result. 
Result so far: 0.0
If we subtract 0 from 12, we get 12.
Fetch the next digit (3) from the dividend, attach it to 12 and continue: 123 / 855

Advancing to step 3:
If we divide 123 by 855, we get 0 and a remainder of 123.
The next digit of our result is 0. 
Result so far: 0.0
If we take 0 away from 123, we end up with 123.
Grab the next digit (9) from the dividend, add it to 123, then carry on: 1239 / 855

Let's proceed to step 4:
The number 855 fits into 1239 1 times, leaving a remainder of 384.
Use 1 as the next digit of our solution. 
Result so far: 1.0
Subtract 855 from 1239 to get 384.
Append the next digit (9) from the dividend to 384 and continue with: 3849 / 855

Going ahead to step 5:
When dividing 3849 by 855, we get 4 with a remainder of 429.
Write down 4 as next digit of the result. 
Result so far: 14.0
Subtracting 3420 from 3849 leaves us with 429.
Fetch the next digit (9) from the dividend, attach it to 429 and continue: 4299 / 855

Moving on to step 6:
855 goes into 4299 5 times with a remainder of 24.
The next digit of our result is 5. 
Result so far: 145.0
Subtracting 4275 from 4299 leaves us with 24.
Append the next digit (8) from the dividend to 24 and continue with: 248 / 855

Step 7:
248 divided by 855 is 0 with a remainder of 248.
Use 0 as the next digit of our solution. 
Result so far: 1450.0
If we take 0 away from 248, we end up with 248.
Since there are no more digits in the dividend, we add a zero to the remainder making it 2480, and continue the process.

Step 8:
When dividing 2480 by 855, we get 2 with a remainder of 770.
Use 2 as the next digit of our solution. 
Result so far: 1450.2
Subtract 1710 from 2480 to get 770.
Since there are no more digits in the dividend, we add a zero to the remainder making it 7700, and continue the process.

Let's proceed to step 9:
7700 divided by 855 is 9 with a remainder of 5.
Record the quotient 9 as the next digit in the result. 
Result so far: 1450.29
Subtract 7695 from 7700 to get 5.
Since there are no more digits in the dividend, we add a zero to the remainder making it 50, and continue the process.

On to step 10:
The number 855 fits into 50 0 times, leaving a remainder of 50.
The next digit of our result is 0. 
Result so far: 1450.29
Subtracting 0 from 50 leaves us with 50.
Since there are no more digits in the dividend, we add a zero to the remainder making it 500, and continue the process.

On to step 11:
If we divide 500 by 855, we get 0 and a remainder of 500.
Use 0 as the next digit of our solution. 
Result so far: 1450.29
Subtracting 0 from 500 leaves us with 500.
Since there are no more digits in the dividend, we add a zero to the remainder making it 5000, and continue the process.

The final result is 1450.29 with a remainder of 0.005.