51212907 divided by 107 
We want to figure out the number of times 51212907 can be divided by 107.

Advancing to step 1:
107 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
Subtract 0 from 5 to get 5.
Take the next digit (1) from the dividend and append it to 5, then repeat: 51 / 107

On to step 2:
The number 107 fits into 51 0 times, leaving a remainder of 51.
Use 0 as the next digit of our solution. 
Result so far: 0.0
Subtract 0 from 51 to get 51.
Take the next digit (2) from the dividend and append it to 51, then repeat: 512 / 107

On to step 3:
107 can be fit into 512 4 times, resulting in a remainder of 84.
The next digit of our result is 4. 
Result so far: 4.0
If we take 428 away from 512, we end up with 84.
Take the next digit (1) from the dividend and append it to 84, then repeat: 841 / 107

Step 4:
The number 107 fits into 841 7 times, leaving a remainder of 92.
Write down 7 as next digit of the result. 
Result so far: 47.0
Deduct 749 from 841 and we're left with 92.
Append the next digit (2) from the dividend to 92 and continue with: 922 / 107

Moving on to step 5:
If we divide 922 by 107, we get 8 and a remainder of 66.
Record the quotient 8 as the next digit in the result. 
Result so far: 478.0
The remainder is 66 after subtracting 856 from 922.
Take the next digit (9) from the dividend and append it to 66, then repeat: 669 / 107

Going ahead to step 6:
107 can be fit into 669 6 times, resulting in a remainder of 27.
Put 6 as the next digit of the answer. 
Result so far: 4786.0
Subtracting 642 from 669 leaves us with 27.
Fetch the next digit (0) from the dividend, attach it to 27 and continue: 270 / 107

Let's proceed to step 7:
When dividing 270 by 107, we get 2 with a remainder of 56.
Use 2 as the next digit of our solution. 
Result so far: 47862.0
The remainder is 56 after subtracting 214 from 270.
Grab the next digit (7) from the dividend, add it to 56, then carry on: 567 / 107

Advancing to step 8:
When dividing 567 by 107, we get 5 with a remainder of 32.
The number 5 becomes the next digit in our result. 
Result so far: 478625.0
If we take 535 away from 567, we end up with 32.
Since there are no more digits in the dividend, we add a zero to the remainder making it 320, and continue the process.

Advancing to step 9:
320 divided by 107 is 2 with a remainder of 106.
Write down 2 as next digit of the result. 
Result so far: 478625.2
Subtracting 214 from 320 leaves us with 106.
Since there are no more digits in the dividend, we add a zero to the remainder making it 1060, and continue the process.

Advancing to step 10:
If we divide 1060 by 107, we get 9 and a remainder of 97.
Use 9 as the next digit of our solution. 
Result so far: 478625.29
Deduct 963 from 1060 and we're left with 97.
Since there are no more digits in the dividend, we add a zero to the remainder making it 970, and continue the process.

Step 11:
107 goes into 970 9 times with a remainder of 7.
Put 9 as the next digit of the answer. 
Result so far: 478625.299
Deduct 963 from 970 and we're left with 7.
Since there are no more digits in the dividend, we add a zero to the remainder making it 70, and continue the process.

The final outcome is 478625.299, with a leftover of 0.0007.