138483 ÷ 42 
The aim is to understand the frequency of 42 in 138483.

Advancing to step 1:
When dividing 1 by 42, we get 0 with a remainder of 1.
Record the quotient 0 as the next digit in the result. 
Result so far: 0.0
If we take 0 away from 1, we end up with 1.
Fetch the next digit (3) from the dividend, attach it to 1 and continue: 13 / 42

Going ahead to step 2:
When dividing 13 by 42, we get 0 with a remainder of 13.
Write down 0 as next digit of the result. 
Result so far: 0.0
Subtracting 0 from 13 leaves us with 13.
Grab the next digit (8) from the dividend, add it to 13, then carry on: 138 / 42

Going ahead to step 3:
The number 42 fits into 138 3 times, leaving a remainder of 12.
Put 3 as the next digit of the answer. 
Result so far: 3.0
Deduct 126 from 138 and we're left with 12.
Include the next digit (4) from the dividend after 12, then repeat: 124 / 42

Going ahead to step 4:
When dividing 124 by 42, we get 2 with a remainder of 40.
Put 2 as the next digit of the answer. 
Result so far: 32.0
If we subtract 84 from 124, we get 40.
Take the next digit (8) from the dividend and append it to 40, then repeat: 408 / 42

Advancing to step 5:
The number 42 fits into 408 9 times, leaving a remainder of 30.
Record the quotient 9 as the next digit in the result. 
Result so far: 329.0
If we subtract 378 from 408, we get 30.
Append the next digit (3) from the dividend to 30 and continue with: 303 / 42

On to step 6:
42 goes into 303 7 times with a remainder of 9.
Use 7 as the next digit of our solution. 
Result so far: 3297.0
If we subtract 294 from 303, we 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.

On to step 7:
42 can be fit into 90 2 times, resulting in a remainder of 6.
Use 2 as the next digit of our solution. 
Result so far: 3297.2
Subtract 84 from 90 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.

Advancing to step 8:
If we divide 60 by 42, we get 1 and a remainder of 18.
Use 1 as the next digit of our solution. 
Result so far: 3297.21
Subtracting 42 from 60 leaves us with 18.
Since there are no more digits in the dividend, we add a zero to the remainder making it 180, and continue the process.

On to step 9:
42 can be fit into 180 4 times, resulting in a remainder of 12.
The number 4 becomes the next digit in our result. 
Result so far: 3297.214
If we take 168 away from 180, 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 10:
42 goes into 120 2 times with a remainder of 36.
The number 2 becomes the next digit in our result. 
Result so far: 3297.2142
Deduct 84 from 120 and we're left with 36.
Since there are no more digits in the dividend, we add a zero to the remainder making it 360, and continue the process.

Advancing to step 11:
When dividing 360 by 42, we get 8 with a remainder of 24.
The next digit of our result is 8. 
Result so far: 3297.21428
If we subtract 336 from 360, we get 24.
Since there are no more digits in the dividend, we add a zero to the remainder making it 240, and continue the process.

Let's proceed to step 12:
42 goes into 240 5 times with a remainder of 30.
Use 5 as the next digit of our solution. 
Result so far: 3297.214285
Subtract 210 from 240 to get 30.
Since there are no more digits in the dividend, we add a zero to the remainder making it 300, and continue the process.

Let's proceed to step 13:
If we divide 300 by 42, we get 7 and a remainder of 6.
Put 7 as the next digit of the answer. 
Result so far: 3297.2142857
The remainder is 6 after subtracting 294 from 300.
Since there are no more digits in the dividend, we add a zero to the remainder making it 60, and continue the process.

Moving on to step 14:
If we divide 60 by 42, we get 1 and a remainder of 18.
Use 1 as the next digit of our solution. 
Result so far: 3297.21428571
Deduct 42 from 60 and we're left with 18.
Since there are no more digits in the dividend, we add a zero to the remainder making it 180, and continue the process.

The final outcome is 3297.21428571, with a leftover of 1.8e-08.