We look at the division of 37966119 by 15 
The aim is to understand the frequency of 15 in 37966119.

Step 1:
15 goes into 3 0 times with a remainder of 3.
Record the quotient 0 as the next digit in the result. 
Result so far: 0.0
Subtract 0 from 3 to get 3.
Include the next digit (7) from the dividend after 3, then repeat: 37 / 15

Let's proceed to step 2:
When dividing 37 by 15, we get 2 with a remainder of 7.
The next digit of our result is 2. 
Result so far: 2.0
Deduct 30 from 37 and we're left with 7.
Bring next digit (9) of the dividend behind the 7 and repeat the process: 79 / 15

Step 3:
The number 15 fits into 79 5 times, leaving a remainder of 4.
Use 5 as the next digit of our solution. 
Result so far: 25.0
Subtract 75 from 79 to get 4.
Append the next digit (6) from the dividend to 4 and continue with: 46 / 15

Advancing to step 4:
15 can be fit into 46 3 times, resulting in a remainder of 1.
Use 3 as the next digit of our solution. 
Result so far: 253.0
Subtracting 45 from 46 leaves us with 1.
Grab the next digit (6) from the dividend, add it to 1, then carry on: 16 / 15

Going ahead to step 5:
When dividing 16 by 15, we get 1 with a remainder of 1.
The number 1 becomes the next digit in our result. 
Result so far: 2531.0
Deduct 15 from 16 and we're left with 1.
Grab the next digit (1) from the dividend, add it to 1, then carry on: 11 / 15

Advancing to step 6:
15 goes into 11 0 times with a remainder of 11.
The number 0 becomes the next digit in our result. 
Result so far: 25310.0
The remainder is 11 after subtracting 0 from 11.
Grab the next digit (1) from the dividend, add it to 11, then carry on: 111 / 15

Let's proceed to step 7:
If we divide 111 by 15, we get 7 and a remainder of 6.
Write down 7 as next digit of the result. 
Result so far: 253107.0
Deduct 105 from 111 and we're left with 6.
Append the next digit (9) from the dividend to 6 and continue with: 69 / 15

Moving on to step 8:
The number 15 fits into 69 4 times, leaving a remainder of 9.
Use 4 as the next digit of our solution. 
Result so far: 2531074.0
Subtract 60 from 69 to get 9.
Since there are no more digits in the dividend, we add a zero to the remainder making it 90, and continue the process.

Step 9:
15 can be fit into 90 6 times, resulting in a remainder of 0.
Use 6 as the next digit of our solution. 
Result so far: 2531074.6
Subtracting 90 from 90 leaves us with 0.
Since there are no more digits in the dividend, we add a zero to the remainder making it 0, and continue the process.

Moving on to step 10:
If we divide 0 by 15, we get 0 and a remainder of 0.
The number 0 becomes the next digit in our result. 
Result so far: 2531074.6
Subtract 0 from 0 to get 0.
Since there are no more digits in the dividend, we add a zero to the remainder making it 0, and continue the process.

Step 11:
When dividing 0 by 15, we get 0 with a remainder of 0.
The number 0 becomes the next digit in our result. 
Result so far: 2531074.6
If we subtract 0 from 0, we get 0.
Since there are no more digits in the dividend, we add a zero to the remainder making it 0, and continue the process.

Our division results in 2531074.6 with a remaining 0.0.