We look at the division of 50978435 by 646 
Let's see how many times 646 fits into 50978435.

Step 1:
5 divided by 646 is 0 with a remainder of 5.
Record the quotient 0 as the next digit in the result. 
Result so far: 0.0
Deduct 0 from 5 and we're left with 5.
Take the next digit (0) from the dividend and append it to 5, then repeat: 50 / 646

Let's proceed to step 2:
If we divide 50 by 646, we get 0 and a remainder of 50.
Record the quotient 0 as the next digit in the result. 
Result so far: 0.0
Subtracting 0 from 50 leaves us with 50.
Bring next digit (9) of the dividend behind the 50 and repeat the process: 509 / 646

Going ahead to step 3:
The number 646 fits into 509 0 times, leaving a remainder of 509.
Use 0 as the next digit of our solution. 
Result so far: 0.0
Deduct 0 from 509 and we're left with 509.
Take the next digit (7) from the dividend and append it to 509, then repeat: 5097 / 646

Let's proceed to step 4:
When dividing 5097 by 646, we get 7 with a remainder of 575.
The next digit of our result is 7. 
Result so far: 7.0
Subtracting 4522 from 5097 leaves us with 575.
Grab the next digit (8) from the dividend, add it to 575, then carry on: 5758 / 646

Moving on to step 5:
646 goes into 5758 8 times with a remainder of 590.
The next digit of our result is 8. 
Result so far: 78.0
Subtract 5168 from 5758 to get 590.
Bring next digit (4) of the dividend behind the 590 and repeat the process: 5904 / 646

Moving on to step 6:
5904 divided by 646 is 9 with a remainder of 90.
Record the quotient 9 as the next digit in the result. 
Result so far: 789.0
If we take 5814 away from 5904, we end up with 90.
Fetch the next digit (3) from the dividend, attach it to 90 and continue: 903 / 646

Step 7:
If we divide 903 by 646, we get 1 and a remainder of 257.
Put 1 as the next digit of the answer. 
Result so far: 7891.0
The remainder is 257 after subtracting 646 from 903.
Bring next digit (5) of the dividend behind the 257 and repeat the process: 2575 / 646

Moving on to step 8:
When dividing 2575 by 646, we get 3 with a remainder of 637.
Write down 3 as next digit of the result. 
Result so far: 78913.0
Subtract 1938 from 2575 to get 637.
Since there are no more digits in the dividend, we add a zero to the remainder making it 6370, and continue the process.

Moving on to step 9:
When dividing 6370 by 646, we get 9 with a remainder of 556.
The number 9 becomes the next digit in our result. 
Result so far: 78913.9
If we subtract 5814 from 6370, we get 556.
Since there are no more digits in the dividend, we add a zero to the remainder making it 5560, and continue the process.

Step 10:
646 can be fit into 5560 8 times, resulting in a remainder of 392.
Put 8 as the next digit of the answer. 
Result so far: 78913.98
Subtract 5168 from 5560 to get 392.
Since there are no more digits in the dividend, we add a zero to the remainder making it 3920, and continue the process.

Advancing to step 11:
3920 divided by 646 is 6 with a remainder of 44.
Put 6 as the next digit of the answer. 
Result so far: 78913.986
If we take 3876 away from 3920, we end up with 44.
Since there are no more digits in the dividend, we add a zero to the remainder making it 440, and continue the process.

Advancing to step 12:
646 can be fit into 440 0 times, resulting in a remainder of 440.
The next digit of our result is 0. 
Result so far: 78913.986
If we take 0 away from 440, we end up with 440.
Since there are no more digits in the dividend, we add a zero to the remainder making it 4400, and continue the process.

Step 13:
646 goes into 4400 6 times with a remainder of 524.
Put 6 as the next digit of the answer. 
Result so far: 78913.98606
Deduct 3876 from 4400 and we're left with 524.
Since there are no more digits in the dividend, we add a zero to the remainder making it 5240, and continue the process.

On to step 14:
The number 646 fits into 5240 8 times, leaving a remainder of 72.
The next digit of our result is 8. 
Result so far: 78913.986068
Subtracting 5168 from 5240 leaves us with 72.
Since there are no more digits in the dividend, we add a zero to the remainder making it 720, and continue the process.

Advancing to step 15:
When dividing 720 by 646, we get 1 with a remainder of 74.
Write down 1 as next digit of the result. 
Result so far: 78913.9860681
If we subtract 646 from 720, we get 74.
Since there are no more digits in the dividend, we add a zero to the remainder making it 740, and continue the process.

On to step 16:
If we divide 740 by 646, we get 1 and a remainder of 94.
Use 1 as the next digit of our solution. 
Result so far: 78913.98606811
The remainder is 94 after subtracting 646 from 740.
Since there are no more digits in the dividend, we add a zero to the remainder making it 940, and continue the process.

The final outcome is 78913.98606811, with a leftover of 9.4e-08.