51009909 divided by 816 
We want to figure out the number of times 51009909 can be divided by 816.

Advancing to step 1:
816 can be fit into 5 0 times, resulting in a remainder of 5.
Write down 0 as next digit of the result. 
Result so far: 0.0
If we subtract 0 from 5, we get 5.
Append the next digit (1) from the dividend to 5 and continue with: 51 / 816

Step 2:
816 goes into 51 0 times with a remainder of 51.
The number 0 becomes the next digit in our result. 
Result so far: 0.0
If we subtract 0 from 51, we get 51.
Grab the next digit (0) from the dividend, add it to 51, then carry on: 510 / 816

Step 3:
When dividing 510 by 816, we get 0 with a remainder of 510.
Record the quotient 0 as the next digit in the result. 
Result so far: 0.0
If we take 0 away from 510, we end up with 510.
Fetch the next digit (0) from the dividend, attach it to 510 and continue: 5100 / 816

Let's proceed to step 4:
816 goes into 5100 6 times with a remainder of 204.
Use 6 as the next digit of our solution. 
Result so far: 6.0
Subtracting 4896 from 5100 leaves us with 204.
Take the next digit (9) from the dividend and append it to 204, then repeat: 2049 / 816

Advancing to step 5:
2049 divided by 816 is 2 with a remainder of 417.
Write down 2 as next digit of the result. 
Result so far: 62.0
If we subtract 1632 from 2049, we get 417.
Take the next digit (9) from the dividend and append it to 417, then repeat: 4179 / 816

Let's proceed to step 6:
The number 816 fits into 4179 5 times, leaving a remainder of 99.
Record the quotient 5 as the next digit in the result. 
Result so far: 625.0
Subtracting 4080 from 4179 leaves us with 99.
Include the next digit (0) from the dividend after 99, then repeat: 990 / 816

Going ahead to step 7:
The number 816 fits into 990 1 times, leaving a remainder of 174.
Put 1 as the next digit of the answer. 
Result so far: 6251.0
If we subtract 816 from 990, we get 174.
Include the next digit (9) from the dividend after 174, then repeat: 1749 / 816

Going ahead to step 8:
816 can be fit into 1749 2 times, resulting in a remainder of 117.
The next digit of our result is 2. 
Result so far: 62512.0
Deduct 1632 from 1749 and we're left with 117.
Since there are no more digits in the dividend, we add a zero to the remainder making it 1170, and continue the process.

Going ahead to step 9:
When dividing 1170 by 816, we get 1 with a remainder of 354.
Put 1 as the next digit of the answer. 
Result so far: 62512.1
Subtracting 816 from 1170 leaves us with 354.
Since there are no more digits in the dividend, we add a zero to the remainder making it 3540, and continue the process.

Going ahead to step 10:
The number 816 fits into 3540 4 times, leaving a remainder of 276.
The number 4 becomes the next digit in our result. 
Result so far: 62512.14
If we subtract 3264 from 3540, we get 276.
Since there are no more digits in the dividend, we add a zero to the remainder making it 2760, and continue the process.

On to step 11:
If we divide 2760 by 816, we get 3 and a remainder of 312.
Write down 3 as next digit of the result. 
Result so far: 62512.143
If we take 2448 away from 2760, we end up with 312.
Since there are no more digits in the dividend, we add a zero to the remainder making it 3120, and continue the process.

Let's proceed to step 12:
3120 divided by 816 is 3 with a remainder of 672.
Write down 3 as next digit of the result. 
Result so far: 62512.1433
If we subtract 2448 from 3120, we get 672.
Since there are no more digits in the dividend, we add a zero to the remainder making it 6720, and continue the process.

The final outcome is 62512.1433, with a leftover of 0.00672.