84398758 divided by 12 
Let's see how many times 12 fits into 84398758.

On to step 1:
The number 12 fits into 8 0 times, leaving a remainder of 8.
Write down 0 as next digit of the result. 
Result so far: 0.0
Deduct 0 from 8 and we're left with 8.
Fetch the next digit (4) from the dividend, attach it to 8 and continue: 84 / 12

Going ahead to step 2:
The number 12 fits into 84 7 times, leaving a remainder of 0.
Put 7 as the next digit of the answer. 
Result so far: 7.0
If we subtract 84 from 84, we get 0.
Bring next digit (3) of the dividend behind the 0 and repeat the process: 3 / 12

Advancing to step 3:
12 can be fit into 3 0 times, resulting in a remainder of 3.
The next digit of our result is 0. 
Result so far: 70.0
Deduct 0 from 3 and we're left with 3.
Append the next digit (9) from the dividend to 3 and continue with: 39 / 12

On to step 4:
The number 12 fits into 39 3 times, leaving a remainder of 3.
Write down 3 as next digit of the result. 
Result so far: 703.0
Subtract 36 from 39 to get 3.
Grab the next digit (8) from the dividend, add it to 3, then carry on: 38 / 12

Going ahead to step 5:
If we divide 38 by 12, we get 3 and a remainder of 2.
Record the quotient 3 as the next digit in the result. 
Result so far: 7033.0
Deduct 36 from 38 and we're left with 2.
Bring next digit (7) of the dividend behind the 2 and repeat the process: 27 / 12

Going ahead to step 6:
12 goes into 27 2 times with a remainder of 3.
The next digit of our result is 2. 
Result so far: 70332.0
Deduct 24 from 27 and we're left with 3.
Fetch the next digit (5) from the dividend, attach it to 3 and continue: 35 / 12

Going ahead to step 7:
12 goes into 35 2 times with a remainder of 11.
Put 2 as the next digit of the answer. 
Result so far: 703322.0
If we take 24 away from 35, we end up with 11.
Append the next digit (8) from the dividend to 11 and continue with: 118 / 12

Advancing to step 8:
When dividing 118 by 12, we get 9 with a remainder of 10.
Write down 9 as next digit of the result. 
Result so far: 7033229.0
Deduct 108 from 118 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.

On to step 9:
12 can be fit into 100 8 times, resulting in a remainder of 4.
Use 8 as the next digit of our solution. 
Result so far: 7033229.8
Deduct 96 from 100 and we're left 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 10:
If we divide 40 by 12, we get 3 and a remainder of 4.
The next digit of our result is 3. 
Result so far: 7033229.83
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.

Moving on to step 11:
If we divide 40 by 12, we get 3 and a remainder of 4.
The next digit of our result is 3. 
Result so far: 7033229.833
Deduct 36 from 40 and we're left 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 result is 7033229.833 with a remainder of 0.0004.