51212371 ÷ 263 
We want to figure out the number of times 51212371 can be divided by 263.

Going ahead to step 1:
263 goes into 5 0 times with a remainder of 5.
Record the quotient 0 as the next digit in the result. 
Result so far: 0.0
Subtract 0 from 5 to get 5.
Fetch the next digit (1) from the dividend, attach it to 5 and continue: 51 / 263

Let's proceed to step 2:
When dividing 51 by 263, we get 0 with a remainder of 51.
Put 0 as the next digit of the answer. 
Result so far: 0.0
Subtract 0 from 51 to get 51.
Append the next digit (2) from the dividend to 51 and continue with: 512 / 263

On to step 3:
263 goes into 512 1 times with a remainder of 249.
The number 1 becomes the next digit in our result. 
Result so far: 1.0
Subtracting 263 from 512 leaves us with 249.
Include the next digit (1) from the dividend after 249, then repeat: 2491 / 263

Advancing to step 4:
The number 263 fits into 2491 9 times, leaving a remainder of 124.
The next digit of our result is 9. 
Result so far: 19.0
If we take 2367 away from 2491, we end up with 124.
Include the next digit (2) from the dividend after 124, then repeat: 1242 / 263

Going ahead to step 5:
The number 263 fits into 1242 4 times, leaving a remainder of 190.
Use 4 as the next digit of our solution. 
Result so far: 194.0
If we subtract 1052 from 1242, we get 190.
Take the next digit (3) from the dividend and append it to 190, then repeat: 1903 / 263

Step 6:
When dividing 1903 by 263, we get 7 with a remainder of 62.
The number 7 becomes the next digit in our result. 
Result so far: 1947.0
If we subtract 1841 from 1903, we get 62.
Bring next digit (7) of the dividend behind the 62 and repeat the process: 627 / 263

On to step 7:
263 goes into 627 2 times with a remainder of 101.
Record the quotient 2 as the next digit in the result. 
Result so far: 19472.0
Subtracting 526 from 627 leaves us with 101.
Take the next digit (1) from the dividend and append it to 101, then repeat: 1011 / 263

Going ahead to step 8:
1011 divided by 263 is 3 with a remainder of 222.
Write down 3 as next digit of the result. 
Result so far: 194723.0
Deduct 789 from 1011 and we're left with 222.
Since there are no more digits in the dividend, we add a zero to the remainder making it 2220, and continue the process.

Moving on to step 9:
If we divide 2220 by 263, we get 8 and a remainder of 116.
Record the quotient 8 as the next digit in the result. 
Result so far: 194723.8
If we subtract 2104 from 2220, we get 116.
Since there are no more digits in the dividend, we add a zero to the remainder making it 1160, and continue the process.

Moving on to step 10:
263 can be fit into 1160 4 times, resulting in a remainder of 108.
The next digit of our result is 4. 
Result so far: 194723.84
The remainder is 108 after subtracting 1052 from 1160.
Since there are no more digits in the dividend, we add a zero to the remainder making it 1080, and continue the process.

On to step 11:
263 can be fit into 1080 4 times, resulting in a remainder of 28.
Use 4 as the next digit of our solution. 
Result so far: 194723.844
If we subtract 1052 from 1080, we get 28.
Since there are no more digits in the dividend, we add a zero to the remainder making it 280, and continue the process.

After the division, we end up with 194723.844 and a remainder of 0.0028.