We look at the division of 15643216 by 515 
The aim is to understand the frequency of 515 in 15643216.

Advancing to step 1:
515 goes into 1 0 times with 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.
Append the next digit (5) from the dividend to 1 and continue with: 15 / 515

Let's proceed to step 2:
When dividing 15 by 515, we get 0 with a remainder of 15.
Record the quotient 0 as the next digit in the result. 
Result so far: 0.0
Subtracting 0 from 15 leaves us with 15.
Bring next digit (6) of the dividend behind the 15 and repeat the process: 156 / 515

Going ahead to step 3:
515 goes into 156 0 times with a remainder of 156.
Record the quotient 0 as the next digit in the result. 
Result so far: 0.0
If we subtract 0 from 156, we get 156.
Bring next digit (4) of the dividend behind the 156 and repeat the process: 1564 / 515

Step 4:
If we divide 1564 by 515, we get 3 and a remainder of 19.
Record the quotient 3 as the next digit in the result. 
Result so far: 3.0
Deduct 1545 from 1564 and we're left with 19.
Take the next digit (3) from the dividend and append it to 19, then repeat: 193 / 515

Step 5:
The number 515 fits into 193 0 times, leaving a remainder of 193.
Use 0 as the next digit of our solution. 
Result so far: 30.0
Subtract 0 from 193 to get 193.
Grab the next digit (2) from the dividend, add it to 193, then carry on: 1932 / 515

On to step 6:
515 goes into 1932 3 times with a remainder of 387.
Record the quotient 3 as the next digit in the result. 
Result so far: 303.0
If we take 1545 away from 1932, we end up with 387.
Append the next digit (1) from the dividend to 387 and continue with: 3871 / 515

Advancing to step 7:
When dividing 3871 by 515, we get 7 with a remainder of 266.
Use 7 as the next digit of our solution. 
Result so far: 3037.0
Subtracting 3605 from 3871 leaves us with 266.
Fetch the next digit (6) from the dividend, attach it to 266 and continue: 2666 / 515

Advancing to step 8:
515 can be fit into 2666 5 times, resulting in a remainder of 91.
Put 5 as the next digit of the answer. 
Result so far: 30375.0
Subtract 2575 from 2666 to get 91.
Since there are no more digits in the dividend, we add a zero to the remainder making it 910, and continue the process.

Moving on to step 9:
515 can be fit into 910 1 times, resulting in a remainder of 395.
Put 1 as the next digit of the answer. 
Result so far: 30375.1
Subtracting 515 from 910 leaves us with 395.
Since there are no more digits in the dividend, we add a zero to the remainder making it 3950, and continue the process.

Moving on to step 10:
515 can be fit into 3950 7 times, resulting in a remainder of 345.
Put 7 as the next digit of the answer. 
Result so far: 30375.17
The remainder is 345 after subtracting 3605 from 3950.
Since there are no more digits in the dividend, we add a zero to the remainder making it 3450, and continue the process.

Step 11:
If we divide 3450 by 515, we get 6 and a remainder of 360.
Put 6 as the next digit of the answer. 
Result so far: 30375.176
The remainder is 360 after subtracting 3090 from 3450.
Since there are no more digits in the dividend, we add a zero to the remainder making it 3600, and continue the process.

Step 12:
3600 divided by 515 is 6 with a remainder of 510.
The number 6 becomes the next digit in our result. 
Result so far: 30375.1766
Deduct 3090 from 3600 and we're left with 510.
Since there are no more digits in the dividend, we add a zero to the remainder making it 5100, and continue the process.

Our division results in 30375.1766 with a remaining 0.0051.