851289 divided by 2 
We want to divide 851289 by 2.

On to step 1:
The number 2 fits into 8 4 times, leaving a remainder of 0.
Record the quotient 4 as the next digit in the result. 
Result so far: 4.0
Subtract 8 from 8 to get 0.
Grab the next digit (5) from the dividend, add it to 0, then carry on: 5 / 2

Moving on to step 2:
2 goes into 5 2 times with a remainder of 1.
Record the quotient 2 as the next digit in the result. 
Result so far: 42.0
If we take 4 away from 5, we end up with 1.
Append the next digit (1) from the dividend to 1 and continue with: 11 / 2

On to step 3:
2 goes into 11 5 times with a remainder of 1.
Use 5 as the next digit of our solution. 
Result so far: 425.0
If we subtract 10 from 11, we get 1.
Bring next digit (2) of the dividend behind the 1 and repeat the process: 12 / 2

Advancing to step 4:
When dividing 12 by 2, we get 6 with a remainder of 0.
Put 6 as the next digit of the answer. 
Result so far: 4256.0
Deduct 12 from 12 and we're left with 0.
Append the next digit (8) from the dividend to 0 and continue with: 8 / 2

On to step 5:
2 goes into 8 4 times with a remainder of 0.
Put 4 as the next digit of the answer. 
Result so far: 42564.0
Subtract 8 from 8 to get 0.
Bring next digit (9) of the dividend behind the 0 and repeat the process: 9 / 2

On to step 6:
2 goes into 9 4 times with a remainder of 1.
Use 4 as the next digit of our solution. 
Result so far: 425644.0
Subtracting 8 from 9 leaves us with 1.
Since there are no more digits in the dividend, we add a zero to the remainder making it 10, and continue the process.

On to step 7:
2 goes into 10 5 times with a remainder of 0.
Write down 5 as next digit of the result. 
Result so far: 425644.5
Subtract 10 from 10 to get 0.
Since there are no more digits in the dividend, we add a zero to the remainder making it 0, and continue the process.

Moving on to step 8:
2 goes into 0 0 times with a remainder of 0.
The number 0 becomes the next digit in our result. 
Result so far: 425644.5
If we take 0 away from 0, we end up with 0.
Since there are no more digits in the dividend, we add a zero to the remainder making it 0, and continue the process.

Advancing to step 9:
2 can be fit into 0 0 times, resulting in a remainder of 0.
Record the quotient 0 as the next digit in the result. 
Result so far: 425644.5
Subtract 0 from 0 to get 0.
Since there are no more digits in the dividend, we add a zero to the remainder making it 0, and continue the process.

The final outcome is 425644.5, with a leftover of 0.0.