We're dividing 51549891 by 343 
We want to divide 51549891 by 343.

On to step 1:
5 divided by 343 is 0 with a remainder of 5.
Write down 0 as next digit of the result. 
Result so far: 0.0
Deduct 0 from 5 and we're left with 5.
Append the next digit (1) from the dividend to 5 and continue with: 51 / 343

On to step 2:
If we divide 51 by 343, we get 0 and a remainder of 51.
The number 0 becomes the next digit in our result. 
Result so far: 0.0
Subtract 0 from 51 to get 51.
Include the next digit (5) from the dividend after 51, then repeat: 515 / 343

Let's proceed to step 3:
343 can be fit into 515 1 times, resulting in a remainder of 172.
Record the quotient 1 as the next digit in the result. 
Result so far: 1.0
If we subtract 343 from 515, we get 172.
Grab the next digit (4) from the dividend, add it to 172, then carry on: 1724 / 343

Let's proceed to step 4:
If we divide 1724 by 343, we get 5 and a remainder of 9.
The number 5 becomes the next digit in our result. 
Result so far: 15.0
Subtracting 1715 from 1724 leaves us with 9.
Fetch the next digit (9) from the dividend, attach it to 9 and continue: 99 / 343

Going ahead to step 5:
If we divide 99 by 343, we get 0 and a remainder of 99.
Use 0 as the next digit of our solution. 
Result so far: 150.0
Subtract 0 from 99 to get 99.
Take the next digit (8) from the dividend and append it to 99, then repeat: 998 / 343

Moving on to step 6:
The number 343 fits into 998 2 times, leaving a remainder of 312.
The next digit of our result is 2. 
Result so far: 1502.0
The remainder is 312 after subtracting 686 from 998.
Fetch the next digit (9) from the dividend, attach it to 312 and continue: 3129 / 343

On to step 7:
343 can be fit into 3129 9 times, resulting in a remainder of 42.
Record the quotient 9 as the next digit in the result. 
Result so far: 15029.0
If we take 3087 away from 3129, we end up with 42.
Append the next digit (1) from the dividend to 42 and continue with: 421 / 343

Step 8:
343 goes into 421 1 times with a remainder of 78.
Put 1 as the next digit of the answer. 
Result so far: 150291.0
The remainder is 78 after subtracting 343 from 421.
Since there are no more digits in the dividend, we add a zero to the remainder making it 780, and continue the process.

Moving on to step 9:
When dividing 780 by 343, we get 2 with a remainder of 94.
Record the quotient 2 as the next digit in the result. 
Result so far: 150291.2
The remainder is 94 after subtracting 686 from 780.
Since there are no more digits in the dividend, we add a zero to the remainder making it 940, and continue the process.

Going ahead to step 10:
If we divide 940 by 343, we get 2 and a remainder of 254.
Record the quotient 2 as the next digit in the result. 
Result so far: 150291.22
Deduct 686 from 940 and we're left with 254.
Since there are no more digits in the dividend, we add a zero to the remainder making it 2540, and continue the process.

After the division, we end up with 150291.22 and a remainder of 0.254.