We're dividing 309439 by 91 
We want to divide 309439 by 91.

Moving on to step 1:
91 goes into 3 0 times with a remainder of 3.
The next digit of our result is 0. 
Result so far: 0.0
Subtract 0 from 3 to get 3.
Grab the next digit (0) from the dividend, add it to 3, then carry on: 30 / 91

On to step 2:
91 can be fit into 30 0 times, resulting in a remainder of 30.
The next digit of our result is 0. 
Result so far: 0.0
Subtracting 0 from 30 leaves us with 30.
Append the next digit (9) from the dividend to 30 and continue with: 309 / 91

Step 3:
91 goes into 309 3 times with a remainder of 36.
The number 3 becomes the next digit in our result. 
Result so far: 3.0
If we take 273 away from 309, we end up with 36.
Take the next digit (4) from the dividend and append it to 36, then repeat: 364 / 91

Advancing to step 4:
364 divided by 91 is 4 with a remainder of 0.
Write down 4 as next digit of the result. 
Result so far: 34.0
If we subtract 364 from 364, we get 0.
Bring next digit (3) of the dividend behind the 0 and repeat the process: 3 / 91

Going ahead to step 5:
The number 91 fits into 3 0 times, leaving a remainder of 3.
Put 0 as the next digit of the answer. 
Result so far: 340.0
Subtracting 0 from 3 leaves us with 3.
Take the next digit (9) from the dividend and append it to 3, then repeat: 39 / 91

Moving on to step 6:
91 goes into 39 0 times with a remainder of 39.
Use 0 as the next digit of our solution. 
Result so far: 3400.0
If we subtract 0 from 39, we get 39.
Since there are no more digits in the dividend, we add a zero to the remainder making it 390, and continue the process.

Step 7:
The number 91 fits into 390 4 times, leaving a remainder of 26.
Use 4 as the next digit of our solution. 
Result so far: 3400.4
Subtract 364 from 390 to get 26.
Since there are no more digits in the dividend, we add a zero to the remainder making it 260, and continue the process.

Advancing to step 8:
When dividing 260 by 91, we get 2 with a remainder of 78.
Put 2 as the next digit of the answer. 
Result so far: 3400.42
Deduct 182 from 260 and we're left with 78.
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:
91 goes into 780 8 times with a remainder of 52.
Record the quotient 8 as the next digit in the result. 
Result so far: 3400.428
The remainder is 52 after subtracting 728 from 780.
Since there are no more digits in the dividend, we add a zero to the remainder making it 520, and continue the process.

Advancing to step 10:
The number 91 fits into 520 5 times, leaving a remainder of 65.
The number 5 becomes the next digit in our result. 
Result so far: 3400.4285
The remainder is 65 after subtracting 455 from 520.
Since there are no more digits in the dividend, we add a zero to the remainder making it 650, and continue the process.

Advancing to step 11:
The number 91 fits into 650 7 times, leaving a remainder of 13.
Use 7 as the next digit of our solution. 
Result so far: 3400.42857
Subtract 637 from 650 to get 13.
Since there are no more digits in the dividend, we add a zero to the remainder making it 130, and continue the process.

Going ahead to step 12:
The number 91 fits into 130 1 times, leaving a remainder of 39.
The next digit of our result is 1. 
Result so far: 3400.428571
Deduct 91 from 130 and we're left with 39.
Since there are no more digits in the dividend, we add a zero to the remainder making it 390, and continue the process.

Advancing to step 13:
390 divided by 91 is 4 with a remainder of 26.
The number 4 becomes the next digit in our result. 
Result so far: 3400.4285714
The remainder is 26 after subtracting 364 from 390.
Since there are no more digits in the dividend, we add a zero to the remainder making it 260, and continue the process.

Moving on to step 14:
91 goes into 260 2 times with a remainder of 78.
Use 2 as the next digit of our solution. 
Result so far: 3400.42857142
If we take 182 away from 260, we end up with 78.
Since there are no more digits in the dividend, we add a zero to the remainder making it 780, and continue the process.

After the division, we end up with 3400.42857142 and a remainder of 7.8e-08.