51378404 divided by 815 
We want to figure out the number of times 51378404 can be divided by 815.

On to step 1:
815 can be fit into 5 0 times, resulting in a remainder of 5.
Put 0 as the next digit of the answer. 
Result so far: 0.0
Deduct 0 from 5 and we're left with 5.
Grab the next digit (1) from the dividend, add it to 5, then carry on: 51 / 815

Going ahead to step 2:
If we divide 51 by 815, we get 0 and a remainder of 51.
Put 0 as the next digit of the answer. 
Result so far: 0.0
The remainder is 51 after subtracting 0 from 51.
Include the next digit (3) from the dividend after 51, then repeat: 513 / 815

On to step 3:
If we divide 513 by 815, we get 0 and a remainder of 513.
Put 0 as the next digit of the answer. 
Result so far: 0.0
If we take 0 away from 513, we end up with 513.
Include the next digit (7) from the dividend after 513, then repeat: 5137 / 815

Going ahead to step 4:
815 goes into 5137 6 times with a remainder of 247.
Use 6 as the next digit of our solution. 
Result so far: 6.0
If we subtract 4890 from 5137, we get 247.
Grab the next digit (8) from the dividend, add it to 247, then carry on: 2478 / 815

Advancing to step 5:
815 can be fit into 2478 3 times, resulting in a remainder of 33.
The next digit of our result is 3. 
Result so far: 63.0
The remainder is 33 after subtracting 2445 from 2478.
Include the next digit (4) from the dividend after 33, then repeat: 334 / 815

Let's proceed to step 6:
When dividing 334 by 815, we get 0 with a remainder of 334.
The next digit of our result is 0. 
Result so far: 630.0
Deduct 0 from 334 and we're left with 334.
Append the next digit (0) from the dividend to 334 and continue with: 3340 / 815

On to step 7:
815 can be fit into 3340 4 times, resulting in a remainder of 80.
The next digit of our result is 4. 
Result so far: 6304.0
Deduct 3260 from 3340 and we're left with 80.
Bring next digit (4) of the dividend behind the 80 and repeat the process: 804 / 815

Going ahead to step 8:
815 goes into 804 0 times with a remainder of 804.
Record the quotient 0 as the next digit in the result. 
Result so far: 63040.0
The remainder is 804 after subtracting 0 from 804.
Since there are no more digits in the dividend, we add a zero to the remainder making it 8040, and continue the process.

Step 9:
If we divide 8040 by 815, we get 9 and a remainder of 705.
Put 9 as the next digit of the answer. 
Result so far: 63040.9
If we take 7335 away from 8040, we end up with 705.
Since there are no more digits in the dividend, we add a zero to the remainder making it 7050, and continue the process.

Let's proceed to step 10:
If we divide 7050 by 815, we get 8 and a remainder of 530.
The next digit of our result is 8. 
Result so far: 63040.98
Subtracting 6520 from 7050 leaves us with 530.
Since there are no more digits in the dividend, we add a zero to the remainder making it 5300, and continue the process.

On to step 11:
If we divide 5300 by 815, we get 6 and a remainder of 410.
Record the quotient 6 as the next digit in the result. 
Result so far: 63040.986
Subtracting 4890 from 5300 leaves us with 410.
Since there are no more digits in the dividend, we add a zero to the remainder making it 4100, and continue the process.

On to step 12:
815 can be fit into 4100 5 times, resulting in a remainder of 25.
The next digit of our result is 5. 
Result so far: 63040.9865
Subtracting 4075 from 4100 leaves us with 25.
Since there are no more digits in the dividend, we add a zero to the remainder making it 250, and continue the process.

Let's proceed to step 13:
If we divide 250 by 815, we get 0 and a remainder of 250.
Write down 0 as next digit of the result. 
Result so far: 63040.9865
If we take 0 away from 250, we end up with 250.
Since there are no more digits in the dividend, we add a zero to the remainder making it 2500, and continue the process.

Step 14:
The number 815 fits into 2500 3 times, leaving a remainder of 55.
Use 3 as the next digit of our solution. 
Result so far: 63040.986503
If we subtract 2445 from 2500, we get 55.
Since there are no more digits in the dividend, we add a zero to the remainder making it 550, and continue the process.

Step 15:
The number 815 fits into 550 0 times, leaving a remainder of 550.
The next digit of our result is 0. 
Result so far: 63040.986503
If we subtract 0 from 550, we get 550.
Since there are no more digits in the dividend, we add a zero to the remainder making it 5500, and continue the process.

Step 16:
When dividing 5500 by 815, we get 6 with a remainder of 610.
Use 6 as the next digit of our solution. 
Result so far: 63040.98650306
Deduct 4890 from 5500 and we're left with 610.
Since there are no more digits in the dividend, we add a zero to the remainder making it 6100, and continue the process.

Our division results in 63040.98650306 with a remaining 6.1e-07.