371994 divided by 13 
The aim is to understand the frequency of 13 in 371994.

Let's proceed to step 1:
If we divide 3 by 13, we get 0 and a remainder of 3.
The next digit of our result is 0. 
Result so far: 0.0
Deduct 0 from 3 and we're left with 3.
Include the next digit (7) from the dividend after 3, then repeat: 37 / 13

Advancing to step 2:
13 can be fit into 37 2 times, resulting in a remainder of 11.
The next digit of our result is 2. 
Result so far: 2.0
The remainder is 11 after subtracting 26 from 37.
Grab the next digit (1) from the dividend, add it to 11, then carry on: 111 / 13

On to step 3:
When dividing 111 by 13, we get 8 with a remainder of 7.
The next digit of our result is 8. 
Result so far: 28.0
The remainder is 7 after subtracting 104 from 111.
Grab the next digit (9) from the dividend, add it to 7, then carry on: 79 / 13

Step 4:
The number 13 fits into 79 6 times, leaving a remainder of 1.
Put 6 as the next digit of the answer. 
Result so far: 286.0
Deduct 78 from 79 and we're left with 1.
Fetch the next digit (9) from the dividend, attach it to 1 and continue: 19 / 13

On to step 5:
The number 13 fits into 19 1 times, leaving a remainder of 6.
Write down 1 as next digit of the result. 
Result so far: 2861.0
Deduct 13 from 19 and we're left with 6.
Take the next digit (4) from the dividend and append it to 6, then repeat: 64 / 13

Going ahead to step 6:
64 divided by 13 is 4 with a remainder of 12.
Use 4 as the next digit of our solution. 
Result so far: 28614.0
If we take 52 away from 64, we end up 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.

Moving on to step 7:
If we divide 120 by 13, we get 9 and a remainder of 3.
Write down 9 as next digit of the result. 
Result so far: 28614.9
Subtract 117 from 120 to get 3.
Since there are no more digits in the dividend, we add a zero to the remainder making it 30, and continue the process.

Advancing to step 8:
13 can be fit into 30 2 times, resulting in a remainder of 4.
The next digit of our result is 2. 
Result so far: 28614.92
If we subtract 26 from 30, 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.

Advancing to step 9:
The number 13 fits into 40 3 times, leaving a remainder of 1.
The next digit of our result is 3. 
Result so far: 28614.923
Subtract 39 from 40 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.

On to step 10:
10 divided by 13 is 0 with a remainder of 10.
The next digit of our result is 0. 
Result so far: 28614.923
Deduct 0 from 10 and we're left with 10.
Since there are no more digits in the dividend, we add a zero to the remainder making it 100, and continue the process.

On to step 11:
13 can be fit into 100 7 times, resulting in a remainder of 9.
The next digit of our result is 7. 
Result so far: 28614.92307
If we take 91 away from 100, we end up with 9.
Since there are no more digits in the dividend, we add a zero to the remainder making it 90, and continue the process.

Going ahead to step 12:
13 can be fit into 90 6 times, resulting in a remainder of 12.
Record the quotient 6 as the next digit in the result. 
Result so far: 28614.923076
If we take 78 away from 90, we end up 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.

Let's proceed to step 13:
When dividing 120 by 13, we get 9 with a remainder of 3.
The next digit of our result is 9. 
Result so far: 28614.9230769
If we subtract 117 from 120, we get 3.
Since there are no more digits in the dividend, we add a zero to the remainder making it 30, and continue the process.

Advancing to step 14:
If we divide 30 by 13, we get 2 and a remainder of 4.
Use 2 as the next digit of our solution. 
Result so far: 28614.92307692
Subtracting 26 from 30 leaves us with 4.
Since there are no more digits in the dividend, we add a zero to the remainder making it 40, and continue the process.

After the division, we end up with 28614.92307692 and a remainder of 4e-09.