12017866 ÷ 398 
We want to figure out the number of times 12017866 can be divided by 398.

Moving on to step 1:
If we divide 1 by 398, we get 0 and a remainder of 1.
Record the quotient 0 as the next digit in the result. 
Result so far: 0.0
Deduct 0 from 1 and we're left with 1.
Grab the next digit (2) from the dividend, add it to 1, then carry on: 12 / 398

Let's proceed to step 2:
The number 398 fits into 12 0 times, leaving a remainder of 12.
The next digit of our result is 0. 
Result so far: 0.0
Deduct 0 from 12 and we're left with 12.
Bring next digit (0) of the dividend behind the 12 and repeat the process: 120 / 398

Advancing to step 3:
120 divided by 398 is 0 with a remainder of 120.
The number 0 becomes the next digit in our result. 
Result so far: 0.0
The remainder is 120 after subtracting 0 from 120.
Append the next digit (1) from the dividend to 120 and continue with: 1201 / 398

Going ahead to step 4:
The number 398 fits into 1201 3 times, leaving a remainder of 7.
Put 3 as the next digit of the answer. 
Result so far: 3.0
Deduct 1194 from 1201 and we're left with 7.
Fetch the next digit (7) from the dividend, attach it to 7 and continue: 77 / 398

Advancing to step 5:
77 divided by 398 is 0 with a remainder of 77.
The number 0 becomes the next digit in our result. 
Result so far: 30.0
If we take 0 away from 77, we end up with 77.
Append the next digit (8) from the dividend to 77 and continue with: 778 / 398

Moving on to step 6:
778 divided by 398 is 1 with a remainder of 380.
Use 1 as the next digit of our solution. 
Result so far: 301.0
If we subtract 398 from 778, we get 380.
Include the next digit (6) from the dividend after 380, then repeat: 3806 / 398

Going ahead to step 7:
3806 divided by 398 is 9 with a remainder of 224.
Record the quotient 9 as the next digit in the result. 
Result so far: 3019.0
Deduct 3582 from 3806 and we're left with 224.
Fetch the next digit (6) from the dividend, attach it to 224 and continue: 2246 / 398

Step 8:
398 can be fit into 2246 5 times, resulting in a remainder of 256.
The next digit of our result is 5. 
Result so far: 30195.0
The remainder is 256 after subtracting 1990 from 2246.
Since there are no more digits in the dividend, we add a zero to the remainder making it 2560, and continue the process.

Step 9:
398 can be fit into 2560 6 times, resulting in a remainder of 172.
The next digit of our result is 6. 
Result so far: 30195.6
Deduct 2388 from 2560 and we're left with 172.
Since there are no more digits in the dividend, we add a zero to the remainder making it 1720, and continue the process.

Let's proceed to step 10:
When dividing 1720 by 398, we get 4 with a remainder of 128.
Write down 4 as next digit of the result. 
Result so far: 30195.64
If we take 1592 away from 1720, we end up with 128.
Since there are no more digits in the dividend, we add a zero to the remainder making it 1280, and continue the process.

On to step 11:
1280 divided by 398 is 3 with a remainder of 86.
Record the quotient 3 as the next digit in the result. 
Result so far: 30195.643
The remainder is 86 after subtracting 1194 from 1280.
Since there are no more digits in the dividend, we add a zero to the remainder making it 860, and continue the process.

Going ahead to step 12:
398 goes into 860 2 times with a remainder of 64.
Write down 2 as next digit of the result. 
Result so far: 30195.6432
Subtracting 796 from 860 leaves us with 64.
Since there are no more digits in the dividend, we add a zero to the remainder making it 640, and continue the process.

On to step 13:
When dividing 640 by 398, we get 1 with a remainder of 242.
Write down 1 as next digit of the result. 
Result so far: 30195.64321
If we subtract 398 from 640, we get 242.
Since there are no more digits in the dividend, we add a zero to the remainder making it 2420, and continue the process.

Step 14:
When dividing 2420 by 398, we get 6 with a remainder of 32.
Use 6 as the next digit of our solution. 
Result so far: 30195.643216
The remainder is 32 after subtracting 2388 from 2420.
Since there are no more digits in the dividend, we add a zero to the remainder making it 320, and continue the process.

Moving on to step 15:
320 divided by 398 is 0 with a remainder of 320.
The number 0 becomes the next digit in our result. 
Result so far: 30195.643216
Deduct 0 from 320 and we're left with 320.
Since there are no more digits in the dividend, we add a zero to the remainder making it 3200, and continue the process.

Advancing to step 16:
3200 divided by 398 is 8 with a remainder of 16.
Use 8 as the next digit of our solution. 
Result so far: 30195.64321608
Subtracting 3184 from 3200 leaves us with 16.
Since there are no more digits in the dividend, we add a zero to the remainder making it 160, and continue the process.

Our division results in 30195.64321608 with a remaining 1.6e-08.