We look at the division of 420741 by 3 
The aim is to understand the frequency of 3 in 420741.

Advancing to step 1:
3 can be fit into 4 1 times, resulting in a remainder of 1.
Write down 1 as next digit of the result. 
Result so far: 1.0
Subtract 3 from 4 to get 1.
Include the next digit (2) from the dividend after 1, then repeat: 12 / 3

On to step 2:
3 goes into 12 4 times with a remainder of 0.
Put 4 as the next digit of the answer. 
Result so far: 14.0
Subtract 12 from 12 to get 0.
Include the next digit (0) from the dividend after 0, then repeat: 0 / 3

Moving on to step 3:
3 can be fit into 0 0 times, resulting in a remainder of 0.
Put 0 as the next digit of the answer. 
Result so far: 140.0
The remainder is 0 after subtracting 0 from 0.
Bring next digit (7) of the dividend behind the 0 and repeat the process: 7 / 3

Step 4:
When dividing 7 by 3, we get 2 with a remainder of 1.
The number 2 becomes the next digit in our result. 
Result so far: 1402.0
If we subtract 6 from 7, we get 1.
Bring next digit (4) of the dividend behind the 1 and repeat the process: 14 / 3

Going ahead to step 5:
3 goes into 14 4 times with a remainder of 2.
Write down 4 as next digit of the result. 
Result so far: 14024.0
Subtracting 12 from 14 leaves us with 2.
Bring next digit (1) of the dividend behind the 2 and repeat the process: 21 / 3

On to step 6:
3 can be fit into 21 7 times, resulting in a remainder of 0.
Write down 7 as next digit of the result. 
Result so far: 140247.0
The remainder is 0 after subtracting 21 from 21.
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 7:
0 divided by 3 is 0 with a remainder of 0.
Record the quotient 0 as the next digit in the result. 
Result so far: 140247.0
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.

Let's proceed to step 8:
The number 3 fits into 0 0 times, leaving a remainder of 0.
Write down 0 as next digit of the result. 
Result so far: 140247.0
Subtracting 0 from 0 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.

After the division, we end up with 140247.0 and a remainder of 0.0.