We're dividing 421842 by 79 
Let's see how many times 79 fits into 421842.

On to step 1:
79 can be fit into 4 0 times, resulting in a remainder of 4.
The next digit of our result is 0. 
Result so far: 0.0
The remainder is 4 after subtracting 0 from 4.
Bring next digit (2) of the dividend behind the 4 and repeat the process: 42 / 79

Step 2:
79 goes into 42 0 times with a remainder of 42.
The next digit of our result is 0. 
Result so far: 0.0
Subtract 0 from 42 to get 42.
Grab the next digit (1) from the dividend, add it to 42, then carry on: 421 / 79

Going ahead to step 3:
If we divide 421 by 79, we get 5 and a remainder of 26.
The next digit of our result is 5. 
Result so far: 5.0
If we subtract 395 from 421, we get 26.
Fetch the next digit (8) from the dividend, attach it to 26 and continue: 268 / 79

On to step 4:
268 divided by 79 is 3 with a remainder of 31.
The next digit of our result is 3. 
Result so far: 53.0
Subtract 237 from 268 to get 31.
Include the next digit (4) from the dividend after 31, then repeat: 314 / 79

Moving on to step 5:
If we divide 314 by 79, we get 3 and a remainder of 77.
The number 3 becomes the next digit in our result. 
Result so far: 533.0
Deduct 237 from 314 and we're left with 77.
Take the next digit (2) from the dividend and append it to 77, then repeat: 772 / 79

Step 6:
If we divide 772 by 79, we get 9 and a remainder of 61.
Write down 9 as next digit of the result. 
Result so far: 5339.0
The remainder is 61 after subtracting 711 from 772.
Since there are no more digits in the dividend, we add a zero to the remainder making it 610, and continue the process.

Advancing to step 7:
The number 79 fits into 610 7 times, leaving a remainder of 57.
Record the quotient 7 as the next digit in the result. 
Result so far: 5339.7
Subtracting 553 from 610 leaves us with 57.
Since there are no more digits in the dividend, we add a zero to the remainder making it 570, and continue the process.

Advancing to step 8:
The number 79 fits into 570 7 times, leaving a remainder of 17.
Write down 7 as next digit of the result. 
Result so far: 5339.77
The remainder is 17 after subtracting 553 from 570.
Since there are no more digits in the dividend, we add a zero to the remainder making it 170, and continue the process.

The quotient of the division is 5339.77, and the remainder is 0.017.