We divide 742975 by 3
The aim is to understand the frequency of 3 in 742975.

On to step 1:
If we divide 7 by 3, we get 2 and a remainder of 1.
Write down 2 as next digit of the result. 
Result so far: 2.0
If we take 6 away from 7, we end up with 1.
Append the next digit (4) from the dividend to 1 and continue with: 14 / 3

Let's proceed to step 2:
The number 3 fits into 14 4 times, leaving a remainder of 2.
Record the quotient 4 as the next digit in the result. 
Result so far: 24.0
Subtract 12 from 14 to get 2.
Grab the next digit (2) from the dividend, add it to 2, then carry on: 22 / 3

On to step 3:
If we divide 22 by 3, we get 7 and a remainder of 1.
Record the quotient 7 as the next digit in the result. 
Result so far: 247.0
If we subtract 21 from 22, we get 1.
Grab the next digit (9) from the dividend, add it to 1, then carry on: 19 / 3

Step 4:
3 goes into 19 6 times with a remainder of 1.
Write down 6 as next digit of the result. 
Result so far: 2476.0
Deduct 18 from 19 and we're left with 1.
Append the next digit (7) from the dividend to 1 and continue with: 17 / 3

Going ahead to step 5:
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: 24765.0
Subtracting 15 from 17 leaves us with 2.
Append the next digit (5) from the dividend to 2 and continue with: 25 / 3

On to step 6:
3 goes into 25 8 times with a remainder of 1.
Write down 8 as next digit of the result. 
Result so far: 247658.0
The remainder is 1 after subtracting 24 from 25.
Since there are no more digits in the dividend, we add a zero to the remainder making it 10, and continue the process.

Advancing to step 7:
If we divide 10 by 3, we get 3 and a remainder of 1.
The next digit of our result is 3. 
Result so far: 247658.3
Subtract 9 from 10 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.

Moving on to step 8:
3 can be fit into 10 3 times, resulting in a remainder of 1.
The next digit of our result is 3. 
Result so far: 247658.33
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 result is 247658.33 with a remainder of 0.001.