Let's divide 137287 by 3
The aim is to understand the frequency of 3 in 137287.

Advancing to step 1:
3 can be fit into 1 0 times, resulting in a remainder of 1.
Record the quotient 0 as the next digit in the result. 
Result so far: 0.0
The remainder is 1 after subtracting 0 from 1.
Include the next digit (3) from the dividend after 1, then repeat: 13 / 3

Let's proceed to step 2:
The number 3 fits into 13 4 times, leaving a remainder of 1.
Put 4 as the next digit of the answer. 
Result so far: 4.0
Subtract 12 from 13 to get 1.
Append the next digit (7) from the dividend to 1 and continue with: 17 / 3

On to step 3:
The number 3 fits into 17 5 times, leaving a remainder of 2.
Put 5 as the next digit of the answer. 
Result so far: 45.0
Deduct 15 from 17 and we're left with 2.
Grab the next digit (2) from the dividend, add it to 2, then carry on: 22 / 3

Going ahead to step 4:
The number 3 fits into 22 7 times, leaving a remainder of 1.
The next digit of our result is 7. 
Result so far: 457.0
Deduct 21 from 22 and we're left with 1.
Append the next digit (8) from the dividend to 1 and continue with: 18 / 3

Step 5:
When dividing 18 by 3, we get 6 with a remainder of 0.
Write down 6 as next digit of the result. 
Result so far: 4576.0
If we take 18 away from 18, we end up with 0.
Take the next digit (7) from the dividend and append it to 0, then repeat: 7 / 3

Step 6:
3 goes into 7 2 times with a remainder of 1.
Write down 2 as next digit of the result. 
Result so far: 45762.0
Deduct 6 from 7 and we're left with 1.
Since there are no more digits in the dividend, we add a zero to the remainder making it 10, and continue the process.

Moving on to step 7:
3 goes into 10 3 times with a remainder of 1.
Use 3 as the next digit of our solution. 
Result so far: 45762.3
Deduct 9 from 10 and we're left with 1.
Since there are no more digits in the dividend, we add a zero to the remainder making it 10, and continue the process.

Moving on to step 8:
When dividing 10 by 3, we get 3 with a remainder of 1.
Put 3 as the next digit of the answer. 
Result so far: 45762.33
If we subtract 9 from 10, we 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.

The final outcome is 45762.33, with a leftover of 0.001.