We look at the division of 516721 by 19 
The aim is to understand the frequency of 19 in 516721.

Let's proceed to step 1:
When dividing 5 by 19, we get 0 with a remainder of 5.
The number 0 becomes the next digit in our result. 
Result so far: 0.0
If we subtract 0 from 5, we get 5.
Bring next digit (1) of the dividend behind the 5 and repeat the process: 51 / 19

Going ahead to step 2:
If we divide 51 by 19, we get 2 and a remainder of 13.
Put 2 as the next digit of the answer. 
Result so far: 2.0
If we take 38 away from 51, we end up with 13.
Include the next digit (6) from the dividend after 13, then repeat: 136 / 19

Going ahead to step 3:
19 goes into 136 7 times with a remainder of 3.
Put 7 as the next digit of the answer. 
Result so far: 27.0
Subtracting 133 from 136 leaves us with 3.
Append the next digit (7) from the dividend to 3 and continue with: 37 / 19

Step 4:
19 goes into 37 1 times with a remainder of 18.
The number 1 becomes the next digit in our result. 
Result so far: 271.0
If we subtract 19 from 37, we get 18.
Append the next digit (2) from the dividend to 18 and continue with: 182 / 19

On to step 5:
19 can be fit into 182 9 times, resulting in a remainder of 11.
The next digit of our result is 9. 
Result so far: 2719.0
The remainder is 11 after subtracting 171 from 182.
Include the next digit (1) from the dividend after 11, then repeat: 111 / 19

Going ahead to step 6:
19 can be fit into 111 5 times, resulting in a remainder of 16.
The next digit of our result is 5. 
Result so far: 27195.0
If we subtract 95 from 111, we get 16.
Since there are no more digits in the dividend, we add a zero to the remainder making it 160, and continue the process.

Advancing to step 7:
The number 19 fits into 160 8 times, leaving a remainder of 8.
Use 8 as the next digit of our solution. 
Result so far: 27195.8
Deduct 152 from 160 and we're left with 8.
Since there are no more digits in the dividend, we add a zero to the remainder making it 80, and continue the process.

Step 8:
If we divide 80 by 19, we get 4 and a remainder of 4.
Put 4 as the next digit of the answer. 
Result so far: 27195.84
If we subtract 76 from 80, we get 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 9:
19 can be fit into 40 2 times, resulting in a remainder of 2.
The next digit of our result is 2. 
Result so far: 27195.842
Subtract 38 from 40 to get 2.
Since there are no more digits in the dividend, we add a zero to the remainder making it 20, and continue the process.

Let's proceed to step 10:
If we divide 20 by 19, we get 1 and a remainder of 1.
Record the quotient 1 as the next digit in the result. 
Result so far: 27195.8421
Subtract 19 from 20 to get 1.
Since there are no more digits in the dividend, we add a zero to the remainder making it 10, and continue the process.

Going ahead to step 11:
The number 19 fits into 10 0 times, leaving a remainder of 10.
Use 0 as the next digit of our solution. 
Result so far: 27195.8421
Subtract 0 from 10 to get 10.
Since there are no more digits in the dividend, we add a zero to the remainder making it 100, and continue the process.

Going ahead to step 12:
The number 19 fits into 100 5 times, leaving a remainder of 5.
The number 5 becomes the next digit in our result. 
Result so far: 27195.842105
Subtracting 95 from 100 leaves us with 5.
Since there are no more digits in the dividend, we add a zero to the remainder making it 50, and continue the process.

Moving on to step 13:
If we divide 50 by 19, we get 2 and a remainder of 12.
The next digit of our result is 2. 
Result so far: 27195.8421052
Subtracting 38 from 50 leaves us with 12.
Since there are no more digits in the dividend, we add a zero to the remainder making it 120, and continue the process.

On to step 14:
When dividing 120 by 19, we get 6 with a remainder of 6.
Use 6 as the next digit of our solution. 
Result so far: 27195.84210526
Subtract 114 from 120 to get 6.
Since there are no more digits in the dividend, we add a zero to the remainder making it 60, and continue the process.

The final result is 27195.84210526 with a remainder of 6e-09.