We're dividing 121386 by 39 
The aim is to understand the frequency of 39 in 121386.

Step 1:
The number 39 fits into 1 0 times, leaving a remainder of 1.
Put 0 as the next digit of the answer. 
Result so far: 0.0
Deduct 0 from 1 and we're left with 1.
Append the next digit (2) from the dividend to 1 and continue with: 12 / 39

Let's proceed to step 2:
39 goes into 12 0 times with a remainder of 12.
Put 0 as the next digit of the answer. 
Result so far: 0.0
Subtracting 0 from 12 leaves us with 12.
Append the next digit (1) from the dividend to 12 and continue with: 121 / 39

Advancing to step 3:
39 goes into 121 3 times with a remainder of 4.
The next digit of our result is 3. 
Result so far: 3.0
The remainder is 4 after subtracting 117 from 121.
Append the next digit (3) from the dividend to 4 and continue with: 43 / 39

Going ahead to step 4:
The number 39 fits into 43 1 times, leaving a remainder of 4.
The next digit of our result is 1. 
Result so far: 31.0
If we subtract 39 from 43, we get 4.
Grab the next digit (8) from the dividend, add it to 4, then carry on: 48 / 39

On to step 5:
The number 39 fits into 48 1 times, leaving a remainder of 9.
The next digit of our result is 1. 
Result so far: 311.0
Deduct 39 from 48 and we're left with 9.
Append the next digit (6) from the dividend to 9 and continue with: 96 / 39

Going ahead to step 6:
The number 39 fits into 96 2 times, leaving a remainder of 18.
Use 2 as the next digit of our solution. 
Result so far: 3112.0
The remainder is 18 after subtracting 78 from 96.
Since there are no more digits in the dividend, we add a zero to the remainder making it 180, and continue the process.

Advancing to step 7:
180 divided by 39 is 4 with a remainder of 24.
Put 4 as the next digit of the answer. 
Result so far: 3112.4
The remainder is 24 after subtracting 156 from 180.
Since there are no more digits in the dividend, we add a zero to the remainder making it 240, and continue the process.

Advancing to step 8:
240 divided by 39 is 6 with a remainder of 6.
Put 6 as the next digit of the answer. 
Result so far: 3112.46
Deduct 234 from 240 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.

Step 9:
If we divide 60 by 39, we get 1 and a remainder of 21.
The number 1 becomes the next digit in our result. 
Result so far: 3112.461
Subtracting 39 from 60 leaves us with 21.
Since there are no more digits in the dividend, we add a zero to the remainder making it 210, and continue the process.

On to step 10:
39 can be fit into 210 5 times, resulting in a remainder of 15.
Write down 5 as next digit of the result. 
Result so far: 3112.4615
Deduct 195 from 210 and we're left with 15.
Since there are no more digits in the dividend, we add a zero to the remainder making it 150, and continue the process.

On to step 11:
39 goes into 150 3 times with a remainder of 33.
Record the quotient 3 as the next digit in the result. 
Result so far: 3112.46153
Subtract 117 from 150 to get 33.
Since there are no more digits in the dividend, we add a zero to the remainder making it 330, and continue the process.

On to step 12:
When dividing 330 by 39, we get 8 with a remainder of 18.
Put 8 as the next digit of the answer. 
Result so far: 3112.461538
The remainder is 18 after subtracting 312 from 330.
Since there are no more digits in the dividend, we add a zero to the remainder making it 180, and continue the process.

Advancing to step 13:
180 divided by 39 is 4 with a remainder of 24.
The next digit of our result is 4. 
Result so far: 3112.4615384
Deduct 156 from 180 and we're left with 24.
Since there are no more digits in the dividend, we add a zero to the remainder making it 240, and continue the process.

Advancing to step 14:
When dividing 240 by 39, we get 6 with a remainder of 6.
The next digit of our result is 6. 
Result so far: 3112.46153846
Subtracting 234 from 240 leaves us 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.

Our division results in 3112.46153846 with a remaining 6e-09.