12157510 ÷ 398 
We want to figure out the number of times 12157510 can be divided by 398.

Advancing to step 1:
If we divide 1 by 398, we get 0 and a remainder of 1.
Put 0 as the next digit of the answer. 
Result so far: 0.0
If we subtract 0 from 1, we get 1.
Append the next digit (2) from the dividend to 1 and continue with: 12 / 398

Advancing to step 2:
398 goes into 12 0 times with a remainder of 12.
Use 0 as the next digit of our solution. 
Result so far: 0.0
Subtract 0 from 12 to get 12.
Fetch the next digit (1) from the dividend, attach it to 12 and continue: 121 / 398

Moving on to step 3:
398 goes into 121 0 times with a remainder of 121.
Use 0 as the next digit of our solution. 
Result so far: 0.0
Deduct 0 from 121 and we're left with 121.
Include the next digit (5) from the dividend after 121, then repeat: 1215 / 398

Going ahead to step 4:
1215 divided by 398 is 3 with a remainder of 21.
The next digit of our result is 3. 
Result so far: 3.0
If we subtract 1194 from 1215, we get 21.
Append the next digit (7) from the dividend to 21 and continue with: 217 / 398

Moving on to step 5:
398 goes into 217 0 times with a remainder of 217.
The next digit of our result is 0. 
Result so far: 30.0
Subtracting 0 from 217 leaves us with 217.
Append the next digit (5) from the dividend to 217 and continue with: 2175 / 398

Going ahead to step 6:
398 goes into 2175 5 times with a remainder of 185.
The number 5 becomes the next digit in our result. 
Result so far: 305.0
Subtracting 1990 from 2175 leaves us with 185.
Include the next digit (1) from the dividend after 185, then repeat: 1851 / 398

Advancing to step 7:
1851 divided by 398 is 4 with a remainder of 259.
Record the quotient 4 as the next digit in the result. 
Result so far: 3054.0
If we subtract 1592 from 1851, we get 259.
Include the next digit (0) from the dividend after 259, then repeat: 2590 / 398

Step 8:
398 can be fit into 2590 6 times, resulting in a remainder of 202.
Write down 6 as next digit of the result. 
Result so far: 30546.0
Deduct 2388 from 2590 and we're left with 202.
Since there are no more digits in the dividend, we add a zero to the remainder making it 2020, and continue the process.

Going ahead to step 9:
398 can be fit into 2020 5 times, resulting in a remainder of 30.
The next digit of our result is 5. 
Result so far: 30546.5
The remainder is 30 after subtracting 1990 from 2020.
Since there are no more digits in the dividend, we add a zero to the remainder making it 300, and continue the process.

On to step 10:
300 divided by 398 is 0 with a remainder of 300.
Put 0 as the next digit of the answer. 
Result so far: 30546.5
Subtract 0 from 300 to get 300.
Since there are no more digits in the dividend, we add a zero to the remainder making it 3000, and continue the process.

Moving on to step 11:
When dividing 3000 by 398, we get 7 with a remainder of 214.
Record the quotient 7 as the next digit in the result. 
Result so far: 30546.507
Subtract 2786 from 3000 to get 214.
Since there are no more digits in the dividend, we add a zero to the remainder making it 2140, and continue the process.

Moving on to step 12:
2140 divided by 398 is 5 with a remainder of 150.
Record the quotient 5 as the next digit in the result. 
Result so far: 30546.5075
The remainder is 150 after subtracting 1990 from 2140.
Since there are no more digits in the dividend, we add a zero to the remainder making it 1500, and continue the process.

Let's proceed to step 13:
1500 divided by 398 is 3 with a remainder of 306.
The number 3 becomes the next digit in our result. 
Result so far: 30546.50753
If we take 1194 away from 1500, we end up with 306.
Since there are no more digits in the dividend, we add a zero to the remainder making it 3060, and continue the process.

Step 14:
3060 divided by 398 is 7 with a remainder of 274.
Put 7 as the next digit of the answer. 
Result so far: 30546.507537
If we take 2786 away from 3060, we end up with 274.
Since there are no more digits in the dividend, we add a zero to the remainder making it 2740, and continue the process.

Advancing to step 15:
398 goes into 2740 6 times with a remainder of 352.
Record the quotient 6 as the next digit in the result. 
Result so far: 30546.5075376
Subtract 2388 from 2740 to get 352.
Since there are no more digits in the dividend, we add a zero to the remainder making it 3520, and continue the process.

Let's proceed to step 16:
3520 divided by 398 is 8 with a remainder of 336.
Write down 8 as next digit of the result. 
Result so far: 30546.50753768
Subtract 3184 from 3520 to get 336.
Since there are no more digits in the dividend, we add a zero to the remainder making it 3360, and continue the process.

The quotient of the division is 30546.50753768, and the remainder is 3.36e-07.