51128912 divided by 398 
The aim is to understand the frequency of 398 in 51128912.

Advancing to step 1:
398 can be fit into 5 0 times, resulting in a remainder of 5.
Record the quotient 0 as the next digit in the result. 
Result so far: 0.0
Subtract 0 from 5 to get 5.
Fetch the next digit (1) from the dividend, attach it to 5 and continue: 51 / 398

Step 2:
When dividing 51 by 398, we get 0 with a remainder of 51.
Record the quotient 0 as the next digit in the result. 
Result so far: 0.0
Deduct 0 from 51 and we're left with 51.
Include the next digit (1) from the dividend after 51, then repeat: 511 / 398

Let's proceed to step 3:
398 goes into 511 1 times with a remainder of 113.
Use 1 as the next digit of our solution. 
Result so far: 1.0
If we subtract 398 from 511, we get 113.
Include the next digit (2) from the dividend after 113, then repeat: 1132 / 398

Step 4:
The number 398 fits into 1132 2 times, leaving a remainder of 336.
Write down 2 as next digit of the result. 
Result so far: 12.0
The remainder is 336 after subtracting 796 from 1132.
Grab the next digit (8) from the dividend, add it to 336, then carry on: 3368 / 398

Advancing to step 5:
398 goes into 3368 8 times with a remainder of 184.
Use 8 as the next digit of our solution. 
Result so far: 128.0
If we take 3184 away from 3368, we end up with 184.
Fetch the next digit (9) from the dividend, attach it to 184 and continue: 1849 / 398

Let's proceed to step 6:
The number 398 fits into 1849 4 times, leaving a remainder of 257.
Put 4 as the next digit of the answer. 
Result so far: 1284.0
If we subtract 1592 from 1849, we get 257.
Bring next digit (1) of the dividend behind the 257 and repeat the process: 2571 / 398

Advancing to step 7:
The number 398 fits into 2571 6 times, leaving a remainder of 183.
Use 6 as the next digit of our solution. 
Result so far: 12846.0
Subtracting 2388 from 2571 leaves us with 183.
Grab the next digit (2) from the dividend, add it to 183, then carry on: 1832 / 398

Step 8:
1832 divided by 398 is 4 with a remainder of 240.
Record the quotient 4 as the next digit in the result. 
Result so far: 128464.0
The remainder is 240 after subtracting 1592 from 1832.
Since there are no more digits in the dividend, we add a zero to the remainder making it 2400, and continue the process.

Advancing to step 9:
If we divide 2400 by 398, we get 6 and a remainder of 12.
Record the quotient 6 as the next digit in the result. 
Result so far: 128464.6
Subtract 2388 from 2400 to get 12.
Since there are no more digits in the dividend, we add a zero to the remainder making it 120, and continue the process.

Let's proceed to step 10:
398 goes into 120 0 times with a remainder of 120.
Record the quotient 0 as the next digit in the result. 
Result so far: 128464.6
Subtract 0 from 120 to get 120.
Since there are no more digits in the dividend, we add a zero to the remainder making it 1200, and continue the process.

Advancing to step 11:
When dividing 1200 by 398, we get 3 with a remainder of 6.
The number 3 becomes the next digit in our result. 
Result so far: 128464.603
Deduct 1194 from 1200 and we're left with 6.
Since there are no more digits in the dividend, we add a zero to the remainder making it 60, and continue the process.

On to step 12:
398 goes into 60 0 times with a remainder of 60.
Write down 0 as next digit of the result. 
Result so far: 128464.603
Subtract 0 from 60 to get 60.
Since there are no more digits in the dividend, we add a zero to the remainder making it 600, and continue the process.

Moving on to step 13:
When dividing 600 by 398, we get 1 with a remainder of 202.
Put 1 as the next digit of the answer. 
Result so far: 128464.60301
If we take 398 away from 600, we end up 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.

Step 14:
2020 divided by 398 is 5 with a remainder of 30.
Record the quotient 5 as the next digit in the result. 
Result so far: 128464.603015
Subtracting 1990 from 2020 leaves us with 30.
Since there are no more digits in the dividend, we add a zero to the remainder making it 300, and continue the process.

Going ahead to step 15:
398 can be fit into 300 0 times, resulting in a remainder of 300.
Put 0 as the next digit of the answer. 
Result so far: 128464.603015
If we take 0 away from 300, we end up with 300.
Since there are no more digits in the dividend, we add a zero to the remainder making it 3000, and continue the process.

On to step 16:
When dividing 3000 by 398, we get 7 with a remainder of 214.
The next digit of our result is 7. 
Result so far: 128464.60301507
Deduct 2786 from 3000 and we're left with 214.
Since there are no more digits in the dividend, we add a zero to the remainder making it 2140, and continue the process.

In conclusion, the division gives 128464.60301507 with a balance of 2.14e-07.