16186680 ÷ 398 
We want to figure out the number of times 16186680 can be divided by 398.

Let's proceed to step 1:
398 goes into 1 0 times with a remainder of 1.
The next digit of our result is 0. 
Result so far: 0.0
Deduct 0 from 1 and we're left with 1.
Fetch the next digit (6) from the dividend, attach it to 1 and continue: 16 / 398

On to step 2:
398 goes into 16 0 times with a remainder of 16.
The number 0 becomes the next digit in our result. 
Result so far: 0.0
If we take 0 away from 16, we end up with 16.
Take the next digit (1) from the dividend and append it to 16, then repeat: 161 / 398

Step 3:
If we divide 161 by 398, we get 0 and a remainder of 161.
Write down 0 as next digit of the result. 
Result so far: 0.0
The remainder is 161 after subtracting 0 from 161.
Fetch the next digit (8) from the dividend, attach it to 161 and continue: 1618 / 398

Advancing to step 4:
398 goes into 1618 4 times with a remainder of 26.
The number 4 becomes the next digit in our result. 
Result so far: 4.0
Subtracting 1592 from 1618 leaves us with 26.
Bring next digit (6) of the dividend behind the 26 and repeat the process: 266 / 398

Let's proceed to step 5:
398 can be fit into 266 0 times, resulting in a remainder of 266.
Write down 0 as next digit of the result. 
Result so far: 40.0
Deduct 0 from 266 and we're left with 266.
Grab the next digit (6) from the dividend, add it to 266, then carry on: 2666 / 398

Moving on to step 6:
398 can be fit into 2666 6 times, resulting in a remainder of 278.
Write down 6 as next digit of the result. 
Result so far: 406.0
Subtracting 2388 from 2666 leaves us with 278.
Append the next digit (8) from the dividend to 278 and continue with: 2788 / 398

Step 7:
The number 398 fits into 2788 7 times, leaving a remainder of 2.
Use 7 as the next digit of our solution. 
Result so far: 4067.0
If we subtract 2786 from 2788, we get 2.
Take the next digit (0) from the dividend and append it to 2, then repeat: 20 / 398

Moving on to step 8:
20 divided by 398 is 0 with a remainder of 20.
Use 0 as the next digit of our solution. 
Result so far: 40670.0
If we subtract 0 from 20, we get 20.
Since there are no more digits in the dividend, we add a zero to the remainder making it 200, and continue the process.

Step 9:
The number 398 fits into 200 0 times, leaving a remainder of 200.
Put 0 as the next digit of the answer. 
Result so far: 40670.0
If we take 0 away from 200, we end up with 200.
Since there are no more digits in the dividend, we add a zero to the remainder making it 2000, and continue the process.

Advancing to step 10:
If we divide 2000 by 398, we get 5 and a remainder of 10.
Write down 5 as next digit of the result. 
Result so far: 40670.05
If we take 1990 away from 2000, we end up 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.

Moving on to step 11:
398 can be fit into 100 0 times, resulting in a remainder of 100.
Write down 0 as next digit of the result. 
Result so far: 40670.05
If we subtract 0 from 100, we get 100.
Since there are no more digits in the dividend, we add a zero to the remainder making it 1000, and continue the process.

Moving on to step 12:
398 can be fit into 1000 2 times, resulting in a remainder of 204.
The next digit of our result is 2. 
Result so far: 40670.0502
If we subtract 796 from 1000, we get 204.
Since there are no more digits in the dividend, we add a zero to the remainder making it 2040, and continue the process.

Let's proceed to step 13:
398 can be fit into 2040 5 times, resulting in a remainder of 50.
Use 5 as the next digit of our solution. 
Result so far: 40670.05025
If we subtract 1990 from 2040, we get 50.
Since there are no more digits in the dividend, we add a zero to the remainder making it 500, and continue the process.

Going ahead to step 14:
The number 398 fits into 500 1 times, leaving a remainder of 102.
Put 1 as the next digit of the answer. 
Result so far: 40670.050251
If we take 398 away from 500, we end up with 102.
Since there are no more digits in the dividend, we add a zero to the remainder making it 1020, and continue the process.

Moving on to step 15:
398 can be fit into 1020 2 times, resulting in a remainder of 224.
Use 2 as the next digit of our solution. 
Result so far: 40670.0502512
Subtracting 796 from 1020 leaves us with 224.
Since there are no more digits in the dividend, we add a zero to the remainder making it 2240, and continue the process.

Moving on to step 16:
If we divide 2240 by 398, we get 5 and a remainder of 250.
Use 5 as the next digit of our solution. 
Result so far: 40670.05025125
If we take 1990 away from 2240, we end up with 250.
Since there are no more digits in the dividend, we add a zero to the remainder making it 2500, and continue the process.

The final outcome is 40670.05025125, with a leftover of 2.5e-07.