509225 ÷ 12 
We want to divide 509225 by 12.

Step 1:
When dividing 5 by 12, we get 0 with a remainder of 5.
Record the quotient 0 as the next digit in the result. 
Result so far: 0.0
If we subtract 0 from 5, we get 5.
Bring next digit (0) of the dividend behind the 5 and repeat the process: 50 / 12

Advancing to step 2:
The number 12 fits into 50 4 times, leaving a remainder of 2.
Write down 4 as next digit of the result. 
Result so far: 4.0
Deduct 48 from 50 and we're left with 2.
Bring next digit (9) of the dividend behind the 2 and repeat the process: 29 / 12

Let's proceed to step 3:
12 goes into 29 2 times with a remainder of 5.
The next digit of our result is 2. 
Result so far: 42.0
If we take 24 away from 29, we end up with 5.
Grab the next digit (2) from the dividend, add it to 5, then carry on: 52 / 12

Step 4:
If we divide 52 by 12, we get 4 and a remainder of 4.
Use 4 as the next digit of our solution. 
Result so far: 424.0
Deduct 48 from 52 and we're left with 4.
Take the next digit (2) from the dividend and append it to 4, then repeat: 42 / 12

Advancing to step 5:
The number 12 fits into 42 3 times, leaving a remainder of 6.
Use 3 as the next digit of our solution. 
Result so far: 4243.0
If we subtract 36 from 42, we get 6.
Include the next digit (5) from the dividend after 6, then repeat: 65 / 12

Going ahead to step 6:
12 goes into 65 5 times with a remainder of 5.
The number 5 becomes the next digit in our result. 
Result so far: 42435.0
The remainder is 5 after subtracting 60 from 65.
Since there are no more digits in the dividend, we add a zero to the remainder making it 50, and continue the process.

Let's proceed to step 7:
The number 12 fits into 50 4 times, leaving a remainder of 2.
Write down 4 as next digit of the result. 
Result so far: 42435.4
Subtracting 48 from 50 leaves us with 2.
Since there are no more digits in the dividend, we add a zero to the remainder making it 20, and continue the process.

Moving on to step 8:
The number 12 fits into 20 1 times, leaving a remainder of 8.
Record the quotient 1 as the next digit in the result. 
Result so far: 42435.41
Subtract 12 from 20 to get 8.
Since there are no more digits in the dividend, we add a zero to the remainder making it 80, and continue the process.

Going ahead to step 9:
When dividing 80 by 12, we get 6 with a remainder of 8.
Write down 6 as next digit of the result. 
Result so far: 42435.416
Subtract 72 from 80 to get 8.
Since there are no more digits in the dividend, we add a zero to the remainder making it 80, and continue the process.

Let's proceed to step 10:
12 can be fit into 80 6 times, resulting in a remainder of 8.
The next digit of our result is 6. 
Result so far: 42435.4166
Subtracting 72 from 80 leaves us with 8.
Since there are no more digits in the dividend, we add a zero to the remainder making it 80, and continue the process.

The final outcome is 42435.4166, with a leftover of 8e-05.