Let's divide 353878 by 12
We're looking to find how many times 12 goes into 353878.

Moving on to step 1:
12 goes into 3 0 times with a remainder of 3.
Use 0 as the next digit of our solution. 
Result so far: 0.0
If we take 0 away from 3, we end up with 3.
Grab the next digit (5) from the dividend, add it to 3, then carry on: 35 / 12

Advancing to step 2:
When dividing 35 by 12, we get 2 with a remainder of 11.
Write down 2 as next digit of the result. 
Result so far: 2.0
If we take 24 away from 35, we end up with 11.
Take the next digit (3) from the dividend and append it to 11, then repeat: 113 / 12

Moving on to step 3:
12 goes into 113 9 times with a remainder of 5.
The number 9 becomes the next digit in our result. 
Result so far: 29.0
If we take 108 away from 113, we end up with 5.
Take the next digit (8) from the dividend and append it to 5, then repeat: 58 / 12

Advancing to step 4:
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: 294.0
If we take 48 away from 58, we end up with 10.
Append the next digit (7) from the dividend to 10 and continue with: 107 / 12

Going ahead to step 5:
12 goes into 107 8 times with a remainder of 11.
Put 8 as the next digit of the answer. 
Result so far: 2948.0
If we subtract 96 from 107, we get 11.
Append the next digit (8) from the dividend to 11 and continue with: 118 / 12

Let's proceed to step 6:
The number 12 fits into 118 9 times, leaving a remainder of 10.
Write down 9 as next digit of the result. 
Result so far: 29489.0
The remainder is 10 after subtracting 108 from 118.
Since there are no more digits in the dividend, we add a zero to the remainder making it 100, and continue the process.

Moving on to step 7:
12 goes into 100 8 times with a remainder of 4.
Record the quotient 8 as the next digit in the result. 
Result so far: 29489.8
If we take 96 away from 100, we end up 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:
12 goes into 40 3 times with a remainder of 4.
The number 3 becomes the next digit in our result. 
Result so far: 29489.83
If we take 36 away from 40, we end up 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.

Moving on to step 9:
40 divided by 12 is 3 with a remainder of 4.
Record the quotient 3 as the next digit in the result. 
Result so far: 29489.833
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.

The final outcome is 29489.833, with a leftover of 0.0004.