51879896 ÷ 399 
We want to figure out the number of times 51879896 can be divided by 399.

On to step 1:
399 goes into 5 0 times with a remainder of 5.
The number 0 becomes the next digit in our result. 
Result so far: 0.0
If we take 0 away from 5, we end up with 5.
Include the next digit (1) from the dividend after 5, then repeat: 51 / 399

Advancing to step 2:
399 can be fit into 51 0 times, resulting in a remainder of 51.
Record the quotient 0 as the next digit in the result. 
Result so far: 0.0
Deduct 0 from 51 and we're left with 51.
Bring next digit (8) of the dividend behind the 51 and repeat the process: 518 / 399

Step 3:
When dividing 518 by 399, we get 1 with a remainder of 119.
The next digit of our result is 1. 
Result so far: 1.0
The remainder is 119 after subtracting 399 from 518.
Grab the next digit (7) from the dividend, add it to 119, then carry on: 1197 / 399

Going ahead to step 4:
399 goes into 1197 3 times with a remainder of 0.
Put 3 as the next digit of the answer. 
Result so far: 13.0
If we take 1197 away from 1197, we end up with 0.
Take the next digit (9) from the dividend and append it to 0, then repeat: 9 / 399

On to step 5:
9 divided by 399 is 0 with a remainder of 9.
Write down 0 as next digit of the result. 
Result so far: 130.0
The remainder is 9 after subtracting 0 from 9.
Take the next digit (8) from the dividend and append it to 9, then repeat: 98 / 399

On to step 6:
If we divide 98 by 399, we get 0 and a remainder of 98.
Use 0 as the next digit of our solution. 
Result so far: 1300.0
Subtracting 0 from 98 leaves us with 98.
Bring next digit (9) of the dividend behind the 98 and repeat the process: 989 / 399

Step 7:
The number 399 fits into 989 2 times, leaving a remainder of 191.
Put 2 as the next digit of the answer. 
Result so far: 13002.0
Subtracting 798 from 989 leaves us with 191.
Bring next digit (6) of the dividend behind the 191 and repeat the process: 1916 / 399

Advancing to step 8:
1916 divided by 399 is 4 with a remainder of 320.
Use 4 as the next digit of our solution. 
Result so far: 130024.0
Subtracting 1596 from 1916 leaves us with 320.
Since there are no more digits in the dividend, we add a zero to the remainder making it 3200, and continue the process.

Step 9:
The number 399 fits into 3200 8 times, leaving a remainder of 8.
The number 8 becomes the next digit in our result. 
Result so far: 130024.8
Subtract 3192 from 3200 to get 8.
Since there are no more digits in the dividend, we add a zero to the remainder making it 80, and continue the process.

Advancing to step 10:
80 divided by 399 is 0 with a remainder of 80.
Use 0 as the next digit of our solution. 
Result so far: 130024.8
Deduct 0 from 80 and we're left with 80.
Since there are no more digits in the dividend, we add a zero to the remainder making it 800, and continue the process.

Moving on to step 11:
If we divide 800 by 399, we get 2 and a remainder of 2.
The next digit of our result is 2. 
Result so far: 130024.802
Subtracting 798 from 800 leaves us with 2.
Since there are no more digits in the dividend, we add a zero to the remainder making it 20, and continue the process.

Going ahead to step 12:
The number 399 fits into 20 0 times, leaving a remainder of 20.
The next digit of our result is 0. 
Result so far: 130024.802
The remainder is 20 after subtracting 0 from 20.
Since there are no more digits in the dividend, we add a zero to the remainder making it 200, and continue the process.

Going ahead to step 13:
200 divided by 399 is 0 with a remainder of 200.
Record the quotient 0 as the next digit in the result. 
Result so far: 130024.802
Deduct 0 from 200 and we're left with 200.
Since there are no more digits in the dividend, we add a zero to the remainder making it 2000, and continue the process.

The quotient of the division is 130024.802, and the remainder is 0.0002.