428338 divided by 12 
We're looking to find how many times 12 goes into 428338.

Step 1:
4 divided by 12 is 0 with a remainder of 4.
Put 0 as the next digit of the answer. 
Result so far: 0.0
The remainder is 4 after subtracting 0 from 4.
Include the next digit (2) from the dividend after 4, then repeat: 42 / 12

On to step 2:
If we divide 42 by 12, we get 3 and a remainder of 6.
Record the quotient 3 as the next digit in the result. 
Result so far: 3.0
If we take 36 away from 42, we end up with 6.
Fetch the next digit (8) from the dividend, attach it to 6 and continue: 68 / 12

Going ahead to step 3:
12 goes into 68 5 times with a remainder of 8.
The next digit of our result is 5. 
Result so far: 35.0
The remainder is 8 after subtracting 60 from 68.
Append the next digit (3) from the dividend to 8 and continue with: 83 / 12

Step 4:
The number 12 fits into 83 6 times, leaving a remainder of 11.
The next digit of our result is 6. 
Result so far: 356.0
Subtract 72 from 83 to get 11.
Bring next digit (3) of the dividend behind the 11 and repeat the process: 113 / 12

Advancing to step 5:
If we divide 113 by 12, we get 9 and a remainder of 5.
Put 9 as the next digit of the answer. 
Result so far: 3569.0
Deduct 108 from 113 and we're left with 5.
Grab the next digit (8) from the dividend, add it to 5, then carry on: 58 / 12

Moving on to step 6:
If we divide 58 by 12, we get 4 and a remainder of 10.
Record the quotient 4 as the next digit in the result. 
Result so far: 35694.0
Deduct 48 from 58 and we're left with 10.
Since there are no more digits in the dividend, we add a zero to the remainder making it 100, and continue the process.

Advancing to step 7:
100 divided by 12 is 8 with a remainder of 4.
Record the quotient 8 as the next digit in the result. 
Result so far: 35694.8
Subtracting 96 from 100 leaves us with 4.
Since there are no more digits in the dividend, we add a zero to the remainder making it 40, and continue the process.

Let's proceed to step 8:
When dividing 40 by 12, we get 3 with a remainder of 4.
The number 3 becomes the next digit in our result. 
Result so far: 35694.83
Subtracting 36 from 40 leaves us with 4.
Since there are no more digits in the dividend, we add a zero to the remainder making it 40, and continue the process.

Going ahead to step 9:
When dividing 40 by 12, we get 3 with a remainder of 4.
Put 3 as the next digit of the answer. 
Result so far: 35694.833
Subtract 36 from 40 to get 4.
Since there are no more digits in the dividend, we add a zero to the remainder making it 40, and continue the process.

The final outcome is 35694.833, with a leftover of 0.0004.