We're dividing 646864 by 45 
We're looking to find how many times 45 goes into 646864.

Going ahead to step 1:
45 can be fit into 6 0 times, resulting in a remainder of 6.
Write down 0 as next digit of the result. 
Result so far: 0.0
If we subtract 0 from 6, we get 6.
Grab the next digit (4) from the dividend, add it to 6, then carry on: 64 / 45

Moving on to step 2:
When dividing 64 by 45, we get 1 with a remainder of 19.
Write down 1 as next digit of the result. 
Result so far: 1.0
Subtracting 45 from 64 leaves us with 19.
Grab the next digit (6) from the dividend, add it to 19, then carry on: 196 / 45

Moving on to step 3:
45 goes into 196 4 times with a remainder of 16.
The number 4 becomes the next digit in our result. 
Result so far: 14.0
If we subtract 180 from 196, we get 16.
Take the next digit (8) from the dividend and append it to 16, then repeat: 168 / 45

On to step 4:
If we divide 168 by 45, we get 3 and a remainder of 33.
Use 3 as the next digit of our solution. 
Result so far: 143.0
The remainder is 33 after subtracting 135 from 168.
Bring next digit (6) of the dividend behind the 33 and repeat the process: 336 / 45

Let's proceed to step 5:
45 can be fit into 336 7 times, resulting in a remainder of 21.
Put 7 as the next digit of the answer. 
Result so far: 1437.0
Deduct 315 from 336 and we're left with 21.
Append the next digit (4) from the dividend to 21 and continue with: 214 / 45

Moving on to step 6:
45 goes into 214 4 times with a remainder of 34.
The number 4 becomes the next digit in our result. 
Result so far: 14374.0
Deduct 180 from 214 and we're left with 34.
Since there are no more digits in the dividend, we add a zero to the remainder making it 340, and continue the process.

Moving on to step 7:
340 divided by 45 is 7 with a remainder of 25.
Write down 7 as next digit of the result. 
Result so far: 14374.7
The remainder is 25 after subtracting 315 from 340.
Since there are no more digits in the dividend, we add a zero to the remainder making it 250, and continue the process.

Step 8:
If we divide 250 by 45, we get 5 and a remainder of 25.
Write down 5 as next digit of the result. 
Result so far: 14374.75
The remainder is 25 after subtracting 225 from 250.
Since there are no more digits in the dividend, we add a zero to the remainder making it 250, and continue the process.

On to step 9:
250 divided by 45 is 5 with a remainder of 25.
Record the quotient 5 as the next digit in the result. 
Result so far: 14374.755
The remainder is 25 after subtracting 225 from 250.
Since there are no more digits in the dividend, we add a zero to the remainder making it 250, and continue the process.

After the division, we end up with 14374.755 and a remainder of 0.0025.